Estimation
The ability to estimate is a valuable skill
which needs constant practice. The
Estimation Units help to develop the skills of
estimation over a range of topics. Students
come to the understanding that estimation is
a guide, not the correct answer.
Students estimate length, area, time, groups
and answers to algorithms involving the four
operations. They use rounding to assist in
operations.
There are two assessment pages and an
activity page.
61
Targeting Maths © Blake Publishing 2012.
Middle Primary
Estimation
Unit 1
Area
Length
Time
Groups
Content Descriptions
Number and place value: ACMNA0291
Use efficient mental and written strategies and apply
appropriate digital technologies to solve problems.
© Australian Curriculum, Assessment and Reporting Authority 2012
Proficiency Strands
Understanding:
• An estimate is a guide, not the correct answer.
Fluency:
• Estimate
• Estimate
• Estimate
• Estimate
• Estimate
area in square centimetres.
lengths and heights up to 2 metres.
time for regular daily tasks.
the number in a group given a model.
the number in a group without a model.
BLM Content
•
materials needed for each BLM
1.1 Area – estimate; using cubic centimetres; find
actual measurements.
• cubic centimetres
1.2 Body parts – using hand spans, arm spans, finger
spans, feet to measure length.
1.3 Lengths and heights – estimate the heights
and lengths of everyday objects, given a model to
compare.
1.4 Time – estimate the time it takes to do everyday
tasks and plan a timetable accordingly.
1.5 Groups with a model – study how big the model
is to enable estimation of the group.
1.6 More groups – estimating large numbers; groups
of.
1.7 Assessment
• centicubes
1.8 Activity – use estimation and place value to place
house numbers.
Problem solving:
• Use estimation as a checking method.
Reasoning:
• Use known lengths as a guide in estimation.
• Use known groups as a guide in estimation.
Language
estimate, calculate, guess, rounding off, time, actual,
hand span, arm span, nearest, groups
Materials
blank paper, rulers, metre rulers, pencils, centicubes
or Base 10 materials
62
Targeting Maths © Blake Publishing 2012.
Remember
Before starting ensure
each student:
• has a sharp pencil — B or 2B.
• develops the habit of checking.
• understands that an estimate is
different from an exact answer.
*
Estimation Unit 1
Additional Activities
Answers
•
1 Actual answers
a 28
b 28
2 4
•
•
•
Students find other ways to measure objects,
eg using marbles, toothpicks, pencils, etc.
Use estimation wherever possible in the
classroom. eg “Estimate how many people
are buying their lunch today.”
Encourage estimating answers to all algorithms
before the actual answers are worked. The
estimation can be recorded in the margin.
Hold an ‘Estimation Afternoon’. Each pupil
writes one quesion. eg How many stairs to the
upstairs classrooms? How many palings on the
front fence? Children work in teams to write
estimations for all answers and then work out
actual answers.
BLM 1.1
c 22
d 38
BLM 1.2
Teacher check
BLM 1.3
Approximate answers
1 a 2 m 10 cm
b
c 1 m 50 cm
d
2 a 4 m
b
c 4 ½ m
d
3 a 1 m 75 cm
b
c 45 cm
d
1
1
3
3
2
1
m 20
m 70
m
½m
m 20
m 20
cm
cm
cm
cm
BLM 1.4
Teacher check
BLM 1.5
1
2
3
4
5
6
15
40
50
50
14
30
stars
blobs
hashes
diamonds
hearts
triangles
BLM 1.6
1 b 100
2 b 63
3 b 56
c 20
c 10r3
c 4r8
d 10
d 6r3
d 7
e 4
e 7
e 28
f 2
f 21
f 14
BLM 1.7
1 a 16
b 12
2 a 2 m
b 2 m
c 1 m
3 b 70
4 a to brush teeth
c eat breakfast
e dry a cup
5 your hand-span
b wash a hat
d iron a shirt
BLM 1.8
Teacher check
63
Targeting Maths © Blake Publishing 2012.
Area
Estimation 1.1
Name
Date
1
Estimate how many 1 cm cubes it would take to cover the following
shapes. Then find the actual number.
a
b
7
8
2
2
4
3
4
Estimate ___________ Actual ___________Estimate ___________ Actual ___________
c
d
4
4
2
4
2
3
3
3
2
1
Estimate ___________ Actual ___________Estimate ___________ Actual ___________
2 Estimate and then find the actual number of ‘tens’ that it would take to
cover the following shape.
a
Estimate ___________ Actual ___________
64
Number and place value: ACMNA0291 Use efficient mental and written strategies and apply appropriate digital technologies to solve problems.
Understanding: An estimate is a guide, not the correct answer. Fluency: Estimate area in square centimetres.
Targeting Maths © Blake Publishing 2012.
Body Parts
Estimation 1.2
Name
Date
1
Use parts of your body to measure the items listed. Estimate first, and
then find the actual answer.
Add some items of your own to the list.
Object
Hand span
Estimate
Actual
Arm span
Estimate
Actual
Finger span
Estimate
Actual
Your foot
Estimate
Actual
a desk
b school bag
c story book
d whiteboard
e door width
f metre ruler
g
h
Number and place value: ACMNA0291 Use efficient mental and written strategies and apply appropriate digital technologies to solve problems.
Fluency: Estimate lengths and heights up to 2 metres.
65
Targeting Maths © Blake Publishing 2012.
Lengths and Heights
Name
1
Estimation 1.3
Date
Dan is 200 cm tall.
Dan
How tall is:a Toby?
____________
2
b Yani?
____________
c Henry?
____________
d Elli?
____________
b the garage? c the tree?
____________ ____________
d the ladder?
____________
b the path?
____________
d the rake?
____________
The flagpole is 6 metres tall.
How tall is:a the house?
____________
3
The snake is 2 m long.
About how
a the rope?
long is:
____________
66
c the mat?
____________
Number and place value: ACMNA0291 Use efficient mental and written strategies and apply appropriate digital technologies to solve problems.
Understanding: An estimation is a guide, not the correct answer. Fluency: Estimate lengths and heights up to 2 metres.
Reasoning: Use known lengths as a guide in estimation.
Targeting Maths © Blake Publishing 2012.
Time
Name
1
2
Estimation 1.4
Date
Estimate how long it takes you to do the following things. Compare
your answers with those of your classmates.
a brush your teeth ______________ beat lunch
______________
c travel to school
______________ dget dressed
______________
e tie your shoelaces ______________ f complete your homework ______________
g pack your bag
______________ hsharpen your pencil
______________
Josie Bigge is at home during the holidays. Estimate
minutes or hours for her to:
a make her bed
__________________ b have breakfast
c do the cleaning __________________ d clean the car
e do the shopping __________________ f have lunch
g watch TV
__________________ h answer emails
i go jogging
__________________ j have dinner
k read a chapter __________________ l have a shower
the time it takes in
__________________
__________________
__________________
__________________
__________________
__________________
Make up Josie’s timetable of chores according to your estimates of
the time she takes.
_________ wake, shower and dress
_________ make her bed
_________ breakfast
_________ do the cleaning
_________ do the shopping
_________ return home – have a cup of tea
_________ clean the car
_________ have lunch
_________ watch TV
_________ answer email
_________ go jogging
_________ have dinner
_________ read
3
Number and place value: ACMNA0291 Use efficient mental and written strategies and apply appropriate digital technologies to solve problems.
Understanding: An estimation is a guide, not the correct answer. Fluency: Estimate time for regular daily tasks.
67
Targeting Maths © Blake Publishing 2012.
Groups with a Model
Name
1
5
Date
stars.
2
10
10
hashes
#####
#####
4
20
3
Estimate how many are here. ______________
Estimate how many are here. ______________
Estimate how many are here. ______________
4 triangles
68
#########################
#########################
hearts
6
Estimate how many are here. ______________
diamonds
5
Estimate how many are here. ______________
blobs
3
Estimation 1.5
Estimate how many are here. ______________
Number and place value: ACMNA0291 Use efficient mental and written strategies and apply appropriate digital technologies to solve problems.
Understanding: An estimation is a guide, not the correct answer. Fluency Estimate the number in a group given a model.
Reasoning: Use known groups as a guide to estimation.
Targeting Maths © Blake Publishing 2012.
More Groups
Name
1
Date
Estimate the number of stars in the box and answer the following questions.
* **
* *
* *
*
*
*
Estimation 1.6
* ** * ** * ** * ** * ** * ** * ** * ** * **
* * * * * * * * * * * * * * * * * *
* * * *
* * * *
* * * *
* * * *
* *
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
a Estimate
__________ b Actual total
__________
c How many groups of 5? __________ d How many groups of 10?__________
e How many groups of 25? __________ f How many groups of 50?__________
2 Estimate the number of circles and answer the following questions.
a Estimate
__________ b Actual total
__________
c How many groups of 6? __________ d How many groups of 10?__________
e How many groups of 9? __________ f How many groups of 3? __________
3 Estimate the number of squares and answer the following questions.
a Estimate
__________ b Actual total
__________
c How many groups of 12?__________ d How many groups of 8? __________
e How many groups of 2? __________ f How many groups of 4? __________
Number and place value: ACMNA0291 Use efficient mental and written strategies and apply appropriate digital technologies to solve problems.
Fluency: Estimate the number in a group without a model.
69
Targeting Maths © Blake Publishing 2012.
Assessment • Estimation
Date
Name
1
Estimation 1.7
Estimate how many 1 cm cubes it will take to cover these shapes.
Check your answer by using the cubes.
a b
Estimate __________ Actual __________ Estimate __________ Actual __________
2
The ceiling is 3 metres high. About how high is the:
a top of the door?
___________________
b top of the board?
___________________
c top of the bookshelf? ___________________
3
Estimate how many stars are in the box and then count them to
give the actual answer.
*
* * *
* * *
* * *
* * *
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
* * * * * * * * * * * * * * * * * * * *
* * * * * * * * * * * * * * * * * * * *
*
a Estimate ____________
4
Which would take less time?
a to brush your teeth or eat dinner
b to walk a kilometre or wash a hat
c to eat breakfast or vacuum the house
d watch a half-hour show or iron a shirt
e clean a pair of shoes or dry a cup
5
If you measured a room with your step, your hand-span and your foot,
which one would have the most to count? Why?
____________________________________________________________________________________________
____________________________________________________________________________________________
70
Targeting Maths © Blake Publishing 2012.
b Actual total ____________
_________________________
_________________________
_________________________
_________________________
_________________________
Activity • Estimation
Name
Estimation 1.8
Date
Complete the following
a Estimate the area of the grid below ______________________
b Trace your hand on the cm grid paper below and shade it in.
Estimate its area. ______________________
c Calculate the area of your hand using the cm squares ______________________
d Estimate the area of the grid paper not shaded in. ______________________
2
With a partner calculate how long it takes to:
a jump 10 times. _______ b write your name. _______ c count to twenty by 2s. _______
1
3 Now estimate how many times you can do these things in a minute.
a jump 10 times.
b write your name.
Estimate ________ actual ________ Estimate ________ actual ________
c count to twenty by 2s. Estimate ________ actual ________
71
Targeting Maths © Blake Publishing 2012.
Middle Primary
Estimation
Unit 2
Rounding
Addition
Subtraction
Multiplication
Mixed operations
Content Descriptions
Number and place value: ACMNA0291
Use efficient mental and written strategies and apply
appropriate digital technologies to solve problems.
© Australian Curriculum, Assessment and Reporting Authority 2012
Proficiency Strands
Understanding:
• Rounding can be used as an estimation strategy.
• An estimate is a guide, not the correct answer.
Fluency:
• Round numbers to the nearest 10, 100 and 1 000.
• Round numbers to the nearest 10 000.
• Estimate answers to addition, subtraction and
multiplication problems.
Problem solving:
• Pose questions and solve problems.
Reasoning:
• Use known facts to consider if estimates are
reasonable.
BLM Content
•
materials needed for each BLM
2.1 Rounding – round numbers to the nearest
10, 100 and 1 000, and consider if the estimate of
addition algorithms is reasonable.
2.2 Rounding to ten thousand – round numbers to
the nearest ten thousand.
• coloured pencils
2.3 Estimating addition – use rounding to estimate
the total of 3 digit numbers.
2.4 Estimating subtraction – use rounding to
estimate the difference between two 3-digit numbers.
2.5 Estimating multiplication – use rounding to
estimate the cost of different items for a party.
2.6 Operations – estimate answers to different
algorithms using the 4 different operations; use a
calculator to find the actual answer and then discuss if
the estimate provided is reasonable.
• calculators
2.7 Assessment
Language
estimate, round, total, difference, multiply, tens,
hundred, thousands, ten thousands
Materials
coloured pencils, calculators
72
Targeting Maths © Blake Publishing 2012.
Remember
Before starting ensure that
each student:
• has a sharp B or 2B pencil.
• develops the habit of checking.
• reads questions twice to avoid
simple mistakes.
*
Estimation Unit 2
Additional Activities
•
•
•
Use shopping catalogues, have children go on a
shopping spree. Students can select items and
then estimate the cost of their total shopping bag.
Students estimate the number of children in the
school. Ask children to make a general estimation
and then gather the numbers of children in each
class. Round the numbers to the nearest ten
and total the results. They can then compare this
result with the exact number of children enrolled
in the school, and consider if their estimates were
reasonable.
Children investigate the result of adding or
subtracting two odd numbers and two even
numbers. Test this out on a variety of numbers to
determine if the result is consistently odd or even.
Encourage children to consider this information
when estimating answers. Will the actual result
be odd or even? Do the same for adding and
subtracting a mixture of even and odd numbers.
Answers
20
60
40
200
800
900
3 000
5 000
2 000
no
yes
b 40
f 20
c 80
g 40
d 20
h 60
b 300
f 700
c 500
g 300
d 100
h 700
b
e
h
b
f
c
f
i
c
6 000
2 000
8 000
yes
yes
7 000
9 000
6 000
yes
d no
BLM 2.2
1 a 20 000 b 20 000 c 70 000 d 80 000
e 40 000 f 50 000
g 70 000 h 80 000
i 30 000
2 a 50 000 b 50 000 c 40 000
3 Red: 55 000, 57 030, 55 001, 59 500, 55 999, 63 234
Blue: 53 067, 54 030, 50 002, 46 310, 52 103, 51 987
4 a 70 000 b 70 000 c 20 000 d 160 000
BLM 2.3
1
b
c
d
e
f
300
900
300
500
600
+
+
+
+
+
300
700
300
300
300
=
=
=
=
=
600
1 600
600
800
900
400 + 300 = 700
600 + 200 = 800
900 + 300 = 1 200
700 + 200 = 900
500 + 400 = 900
600 + 300 = 900
400 + 200 = 600
700
b 800
1 000
f 1 000
1 400
j 800
c 600
g 300
d 900
h 800
BLM 2.4
1
2
a
b
c
d
e
f
a
d
3 a
800 –
800 –
700 –
400 –
900 –
900 –
600
400
600
300
400
200
200
400
500
= 500
= 400
= 500
= 200
= 500
= 400
b 100
e 400
b 300
c 500
BLM 2.5
BLM 2.1
1 a
e
i
2 a
e
i
3 a
d
g
4 a
e
2 a
b
c
d
e
f
g
3 a
e
i
1
2
3
a
c
e
a
a
$5.00
$1.00 × 9 = $9.00
90 × 9 = $8.10
$38.10
240 b 160
b 70 × 8 = $5.60
d 80 × 8 = $6.40
f $1.00 × 4 = $4.00
c 350
d 810
BLM 2.6
1
a
b
c
d
e
f
g
h
i
j
est 400
est 400
est 180
est
50
est 900
est 500
est 270
est 300
est 1 100
est 800
actual 380
actual 415
actual 162
actual 49.3
actual 921
actual 525
actual 261
actual 298.6
actual 1 076
actual 819
BLM 2.7
a 500
b 100
a 4 000
b 15 000
a 30 000 b 50 000
a 300 + 600 = 900
c 80 × 5 = 400
5 a False
b True
d True
6 a 170
b 50
7 a $600
b $160
8 a $500
1
2
3
4
c
c
c
b
1 500
4 000
70 000
1 000 – 400 = 600
c True
73
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Rounding
Estimation 2.1
Name
Date
1
Round the following numbers to the nearest 10.
a 15 ____________
b 42 ____________
c 82 ____________
d 22 ____________
e 55 ____________
f 19 ____________
g 39 ____________
h 63 ____________
i 35 ____________
2 Round the following numbers to the nearest 100.
a 152 ____________
b 310 ____________
c 450 ____________
d 30 ____________
e 750 ____________
f 721 ____________
g 267 ____________
h 683 ____________
i 888 ____________
3 Round the following numbers to the nearest 1 000.
a 3 267 ____________
b 5 555 ____________
c 7 136 ____________
d 4 500 ____________
e 2 230 ____________
f 8 917 ____________
g 1 644 ____________
h 7 896 ____________
i 6 499 ____________
4
Estimates to the following questions have been given. State whether
this is a reasonable estimate or not, and give a reason for your answer.
a 263 + 342 = estimate = 500
Reasonable? Yes/No
Why? _____________________________________________________________
b 489 + 362 =
estimate = 800
Reasonable? Yes/No
Why? _____________________________________________________________
c 177 + 446 =
estimate = 600
Reasonable? Yes/No
Why? _____________________________________________________________
d 336 + 541 =
estimate = 800
Reasonable? Yes/No
Why? _____________________________________________________________
e 162 + 192 =
estimate = 400
Reasonable? Yes/No
Why? _____________________________________________________________
f 98 + 335 =
estimate = 400
Reasonable? Yes/No
Why? _____________________________________________________________
74
Number and place value: ACMNA0291 Use efficient mental and written strategies and apply appropriate digital technologies
to solve problems. Understanding: Rounding can be used as an estimation strategy. Fluency: Round numbers to the nearest 10, 100 and 1 000.
Reasoning: Use known facts to consider if estimates are reasonable.
Targeting Maths © Blake Publishing 2012.
Rounding to Ten Thousands
Name
1
Estimation 2.2
Date
Round to the nearest ten thousand.
b 24 265 ___________
a 15 487 ___________
d 84 554 ___________
e 36 344 ___________
g 74 999 ___________
h 82 501 ___________
c 67 648 ___________
f 45 001 ___________
i 25 000 ___________
2 Draw arrows and write the number to round the
numbers below to the nearest ten thousand.
When rounding
numbers to
the nearest ten
thousand, such as
25 000, round up for
a 5 in the thousands.
40 000
Remember
When rounding
to the nearest
ten thousand,
look at the
number in the
thousands place.
50 000
a 45 000
b 45 500
c 44 999
3 Colour the numbers that round to 60 000 red and
the numbers that round to 50 000 blue.
55 000
59 500
57 030
55 999
54 030
46 310
55 001
63 234
53 067
50 002
52 103
51 987
4 The following table provides the daily attendance to the Melbourne
Cricket test between England and Australia.
Round the figures to the nearest ten thousand and then make a total estimate of
crowd attendance.
Attendance
Round to the nearest 10 000
Day 1
67 149
a
Day 2
68 733
b
Day 3
19 889
c
Using the rounded numbers, estimate
the total attendance over three days
d
Number and place value: ACMNA029 Use efficient mental and written strategies and apply appropriate digital technologies to solve problems.
Understanding: Rounding can be used as an estimation strategy. Fluency: Round numbers to the nearest 10 000. Estimate the total of two numbers.
75
Targeting Maths © Blake Publishing 2012.
Estimating Addition
Estimation 2.3
Name
Date
1
Estimate the answers of the following addition algorithms by rounding
each number first.
a 117
+
238
b 289
+
327
=
c 878
+
650
=
d 289
+
289
=
e 482
+
324
=
f 645
+
331
=
=
100 + 200
2 Use rounding to estimate a reasonable answer to these addition algorisms.
687
700
a 388
+220
+200 +292
900
d 679
+224
e 514
+224 +367
+
b 608
+202
+
+312
+325
+
f 635
+
c 887
+
g 388
+197
+
3 For the following addition algorithms, colour the better estimate.
a 332 + 397 =
600
700
b 542 + 327 =
800
900
c 222 + 397 =
500
600
d 437 + 498 =
900
800
e 777 + 234 =
900
1 000
f 432 + 588 =
1 000
900
g 244 + 102 =
300
400
h 533 + 251 =
800
900
i 987 + 398 =
1 300
14 000
j 109 + 684 =
700
800
76
Number and place value: ACMNA0291 Use efficient mental and written strategies and apply appropriate digital technologies to solve problems.
Understanding: An estimate is a guide, not the correct answer. Fluency: Estimate answers to addition, subtraction and multiplication problems.
Targeting Maths © Blake Publishing 2012.
Estimating Subtraction
Name
1
Estimation 2.4
Date
Round these numbers to the nearest hundred and then estimate
the difference.
a
d
798
– 332
432
– 165
b
_________
e
_________
832
– 426
c
_________
937
– 367
f
_________
742
– 213
_________
922
– 435
_________
2 Round these numbers to the nearest hundred and estimate the difference.
Colour the most reasonable answer.
a 976
b 732 c 842
d 677
e 807
– 432 – 555 – 342 – 288 – 369
3
500
100
600
500
500
600
200
500
400
400
Estimate the answer to these word problems.
Explain how you worked out your answer.
aThere are 832 cars parked in the
bThere are 587 students at Hillville
Bellington shopping car park.
Public School. 189 primary students
231 cars are parked on the top
went to the district athletics
level. Estimate how many cars are
carnival, and 127 students went on
parked on the remaining two levels.
an excursion to the zoo. Estimate
how many students remained at
school?
Number and place value: ACMNA0291 Use efficient mental and written strategies and apply appropriate digital technologies to solve problems.
Understanding: An estimate is a guide, not the correct answer. Fluency: Estimate answers to addition, subtraction and multiplication problems.
77
Targeting Maths © Blake Publishing 2012.
Estimating Multiplication
Name
Estimation 2.5
Date
Mia needs to buy a few extra items for her party. She is on a strict budget, so she
needs to estimate how much it is going to cost before she does her shopping.
She has found these items at super low prices!
soft drink
92c
Super
sale
mini chips
67c
party pies
85c each
1
pack of
balloons
95c
chocolate
bar
81c
cup cakes
99c each
Round the following prices, and estimate how much it will cost to buy:
a 5 cans of soft drink
92c
b 8 packs of mini chips
$1·00
5×
67c
5×
8×
d 8 chocolate bars
×
c 9 cup cakes
8×
e 9 party pies
×
99c
×
×
×
f 4 packs of balloons
×
×
×
2 What is the total estimate of the cost of the party? _____________________
3 Estimate the result by rounding the first factor to the nearest ten.
a 37 × 6
c 73 × 5×
78
40 × 6 =
=
b 42 × 4
×
=
d 94 × 9
×
=
Number and place value: ACMNA0291 Use efficient mental and written strategies and apply appropriate digital technologies to solve problems.
Understanding: An estimate is a guide, not the correct answer. Fluency: Estimate answers to addition, subtraction and multiplication problems.
Targeting Maths © Blake Publishing 2012.
Operations
Estimation 2.6
Name
1
Date
Estimate the answers to the following number problems.
Use your calculator to find the actual answer.
Consider if your estimate is reasonable.
Question
Estimate—(show how you
got your estimate)
Actual
Answer
Was your estimate
Reasonable? Explain
a 163 + 217
b 514 – 99
c 27 × 6
d 148 ÷ 3
e 398 + 523
f 912 – 387
g 29 × 9
h 896 ÷ 3
i 378 + 202 + 496
j 642 + 389 – 212
Number and place value: ACMNA0291 Use efficient mental and written strategies and apply appropriate digital technologies to solve problems.
Understanding: An estimate is a guide, not the correct answer. Fluency: Estimate answers to addition, subtraction and multiplication problems.
79
Targeting Maths © Blake Publishing 2012.
Assessment • Estimation
Estimation 2.7
Date
Name
1
Round the following numbers to the nearest 100.
a 455 ____________
b 132 ____________
c 1 460 ____________
2
Round the following numbers to the nearest 1 000.
a 4 314 ____________
b 15 330 ____________ d 3 500 ____________
3
Round the following numbers to the nearest 10 000.
a 25 788 ____________ b 47 364 ____________ c 65 000 ____________
4 Estimate the following algorithms by rounding first.
Pay close attention to the sign.
a
345
c 78
__________ b 967
__________
– 439
× 5
+ 641
__________
__________
5
The following items were for sale on an online shop.
A
Snakes and Ladders
$22
__________
__________
B
Toy front load washer
$65
C
Watch
$123
D
Camcorder
$287
Use rounding to help you estimate the following answers and then state
whether the total given is true or false.
a A + B is about $80 _____________ b C + D is about $410 _____________
c B + D is about $360 ____________ d A + C is about $150 _____________
6
Estimate the difference in cost between the following items.
Use the back of the sheet for working out.
a D and C ______________________ b B and C ______________________
7
Estimate the cost of buying the following items.
Use the back of the sheet for working out.
a 5 watches ____________
b 8 Snakes and Ladders ____________
8
Estimate the cost of buying all four items.
Was your estimate reasonable? Explain.
Estimate
80
Targeting Maths © Blake Publishing 2012.
Why my estimate is reasonable.