2.2: Addition of Whole Numbers and Decimals
Objective: To review place-value
concepts and the use of the
partial-sums and column-addition
methods.
2.2
Everyday Math
Math Starter
Write these numbers in
expanded notation on your slate:
0.52
52
Reminder
Expanded notation
expresses a number
as the sum of the
values of each digit.
TLG Page 81
Getting Started
2.2
Everyday Math
Math Starter
Write these numbers in
expanded notation on your slate:
Reminder
0.241
241
Expanded notation
expresses a number
as the sum of the
values of each digit.
TLG Page 86
Getting Started
2.2
Everyday Math
Math Starter
Write these numbers in
expanded notation on your slate:
Reminder
0.708
0.084
Expanded notation
expresses a number
as the sum of the
values of each digit.
7,904
TLG Page 86
Getting Started
2.2
Everyday Math
Math Starter Answers
.52= .5+.02
.708=______________________
52= 50+2
.084=______________________
.241= .2+.04+.001
7,904=_____________________
241= 200+40+1
TLG Page 86
Getting Started
2.2
Everyday Math
Place-Value Chart
1,000s
thousands
100s
hundreds
10s
tens
1s
ones
.
0.1s
tenths
0.01s
hundredths
0.001s
thousandths
Think of one true statement you could make
about the base-ten system for numbers.
TLG Page 86
Part 1
2.2
Everyday Math
Place-Value Chart
1,000s
thousands
100s
hundreds
10s
tens
1s
ones
.
0.1s
tenths
0.01s
hundredths
0.001s
thousandths
Pull
Each place has a value that is 10 times the
value of the place to its right.
Each place has a value that is one-tenth
the value of the place to its left.
TLG Page 86
Part 1
2.2
Everyday Math
Place-Value Chart
1,000s
thousands
100s
hundreds
10s
tens
1s
ones
.
0.1s
tenths
0.01s
hundredths
0.001s
thousandths
What is the value of the digit 2 in each of these
numbers? Can you prove your answer using the chart?
a. 20,006.8
b. 0.02
c. 34.502
SRB p. 30
TLG p.86
Part 1
2.2
Everyday Math
Place-Value Chart
1,000s
thousands
100s
hundreds
10s
tens
1s
ones
.
0.1s
tenths
0.01s
hundredths
0.001s
thousandths
Using the digits 9, 3, and 5, what is
a. the smallest decimal that you can write?
b. the largest decimal less than 1 that you can write?
c. the decimal closet to 0.5 that you can write?
SRB p. 30
TLG p.86
Part 1
2.2
Everyday Math
First
Write the numbers 348 and 177
in expanded notation.
Then
Open your SRB to page 13 and read the
section on the partial-sums method.
TLG Page 87
Part 1
2.2
Everyday Math
348 + 177= ?
Expanded notation
+
Partial Sum Method
300 + 40 + 8
100s
10s
1s
100 + 70 + 7
3
4
8
+ 1
7
7
Add the 100s.
4
0
0
Add the 10s.
1
1
0
1
5
2
5
400 + 110 + 15
510 + 15
525
Add the 1s.
Add partial sums.
5
SRB p. 13
TLG P. 87
Part 1
Partial Sums Practice- Class examples!
355
+532
46
+87
678
+345
Partial Sums Practice- Try these examples on your own!
329
+534
277
+ 44
751
+ 79
2.2
Everyday Math
First
Write the numbers 4.56 and 7.9
in expanded notation.
Then
Open your SRB to page 35 and read the
section on the partial-sums method when
you have decimals.
TLG Page 87
Part 1
2.2
Everyday Math
4.56 + 7.09= ?
Expanded notation
+
Partial Sum Method
4 + 0.5 + 0.06
1s
7 + 0.9
4 .
5
6
+ 7 .
9
0
11 .
0
0
Add the tenths.
1 .
4
0
Add the hundredths.
0 .
0
6
12 .
4
6
11 + 1.4 + 0.06
12.4 + 0.06
12.46
Add the ones.
Add partial sums.
0.1s 0.01s
SRB p. 35
TLG P. 87
Part 1
2.2
Everyday Math
Math Journal
Open your journal to page 32
and complete it independently.
Once you have completed it, check
your answers with a partner.
TLG Page 88
Part 1
Wednesday October 12th
1. Check Decimal HW
2. Five minute review- Mean
3. Lesson 2.3 Vocabulary check
4. Using partial sums with decimals
5. Go over pages 32-33 in your Journal.
6. Start 2.3 Lesson
2.2
Everyday Math
Column-Addition Method
Each column of numbers is added separately in any order.
If adding results in a single digit in each column, then
sum has been found.
If the sum in any column is a 2-digit number, it is
renamed and part of it is added to the sum in the
column to its left. (Carrying)
Lets try one!
TLG Page 88
SRB 13
Part 1
Everyday Math
2.2
Practice using the Partial Sums method
Complete the problem assigned to your group. Work
together to make sure everyone understands and agrees
with your answer.
Group 1- 39 + 23
Group 4- 1.56 + 8.72
Group 2- 0.7+ 0.29
Group 5- 7,069 + 3,481
Group 3- 607 + 46 +239
Group 6- 48.26 + 7.94
Be ready to demonstrate how you got your answer.
TLG Page 88
Part 1
2.2
Everyday Math
Column-Addition Method
Turn to page 13 in your SRB and follow along.
359 +298 = ?
Add the numbers in each column.
Adjust the 1s and 10s:
17 ones = 1 ten and 7 ones
Trade the 1 ten into the tens column.
Adjust the 10s and 100s:
15 tens = 1 hundred and 5 tens
Trade the 1 hundred into the
hundreds column.
100s
10s
1s
3
5
9
+ 2
9
8
5
14
17
5
15
7
6
5
7
TLG p. 88
SRB p. 13
Part 1
2.2
Everyday Math
Column-Addition Method with Decimals
Turn to page 35 in your SRB and follow along.
4.56 + 7.9= ?
1s
Add the numbers in each column.
Trade 14 tenths for
one and 4 tenths.
Move the 1 one into
the ones column.
0.1s
0.01s
4 .
5
6
+ 7 .
9
0
11 .
14
6
12 .
4
6
TLG p. 88
SRB p. 35
Part 1
2.2
Everyday Math
Addition Top-It
Try playing this game using decimals.
Draw 4 cards and form 2 numbers that each have
a whole number portion and a decimal portion. Use
counters to represent the decimal point.
Find the sum of the 2 numbers.
TLG Page 89
Part 2