TOPIC
29
Number Sentences
Strand:
Strand unit:
433
434
435
Translate addition, subtraction, multiplication or division number sentences with
a frame into a word problem (frame not in initial position).
Translate a 1-step word problem into a number sentence.
Solve 1-step number sentences.
Looking back: What the 3rd class programme covered
1. Translating addition or subtraction number sentence with a frame into a
word problem.
2. Solving 1-step number sentences.
Maths skills used in this topic
1. Integrating and connecting: Make mathematical connections within mathematics itself,
throughout other subjects, and in applications of mathematics in practical everyday contexts.
2. Reasoning: Reason, investigate and hypothesise with patterns and relationships in mathematics.
Dice, dice with operation signs
Vocabulary
Maximum, minimum
Teaching points
1. Use a scale balance to demonstrate equality. Whatever action happens to one side of the
balance, the same must happen to the other if they are to remain balanced. The same
principle applies to number sentences.
2. Remind the children that there is very little new here, that they have been working with sums
= 10 since 1st class.
such as 6 +
Dice:
With a partner, roll three numbers and an operation dice.
How many number sentences can you make? Record your answers.
109
Target board 1:
1. Teacher to pick 2 numbers, 16 + 6 add them, find the answer. (22) Then ask the children,
= 22). Ask the children to make up
‘What number added to 16 will give me 22?’ (16 +
their own number sentences.
2. Look for 3 numbers that are connected by an addition or subtraction fact, e.g. 18, 27, 45.
Write down the number sentence. If 18 + 27 = 45, then 45 - 18 = 27 and 45 - 27 = 18.
Consider other patterns of similar calculations.
Topic suggestions
1. Using < or > in a number sentence is easier than using = because there are lots of possible
right answers. 4 + 5 <12 and 4 + 7 <12 are equally valid. It gets a little harder when we
require the greatest possible whole number to fill the blank (or the smallest possible in 4 +
=
>12, for example). Children will soon see that the easiest way to do this is to solve 4 +
12 and then add or subtract 1 unit.
2. Note that curriculum expressly says ‘frame not in initial position’. Confine the number
sentences to having the blank second or last.
Activity A
What number must be placed with the weight on the left to make the two weights balance?
What if these numbers were in the weights:
LHS 20
Try some open ones:
RHS 25 –
LHS 20
RHS 4 x
LHS 5
12 =
+
15 =
x
8=
÷
RHS 30 ÷
Differentiation
Lower attainers:
Refer to photocopiable.
Higher attainers:
Ask the children to make 1-step and 2-step number sentences in which the operator is missing.
Stage 2: Include brackets
Stage 1:
1. 4
2. 15
110
9 = 13
3 = 12
3. 5
8 = 40
4. 63
9=7
1. (4
2. (14
3)
2)
1 = 11
3 = 21
Their partners then have to solve the sums by finding the correct operator(s).
Topic
29
1. Fill the missing numbers.
(a)
(b)
8+
6+
17
(c)
20
(d)
12 –
20 –
9
(e)
4
(f)
6x
9x
48
(g)
72
(h)
44 ÷
54 ÷
11
2. (a) 3 + ____ = 11
(b) 20 + ____ = 28
(d) 8 + ____ = 16
(e) 30 + ____ = 32
(g) 7 + ____ = 14
(h) 40 + ____ = 43
(j) 6 + ____ = 18
(k) 50 + ____ = 66
(m) 3 + ____ = 20
6
(c) 18 +
= 30
= 28
(f) 22 +
(n) 60 + ____ = 79
(i) 33 +
= 44
(l) 41 +
= 56
= 69
(o) 55 +
3. Complete these open sentences.
(a) 10 =
+
(d) 25 =
+
(g) 18 =
+
+
(b) 16 =
+
(e) 30 =
+
(h) 30 =
+
+
+
(f) 15 =
+
(i) 100 =
+
(e) 45
+2
72
(f) 39
+ 8
87
6
1
1
6
6
1
7
2
2
7
7
2
8
3
3
8
8
3
9
4
4
9
9
4
Name: _______________________________________
+
+
© Folens Photocopiables
4. Can you fill the blanks? Tick the correct answers.
(d) 56
(a) 4
(b) 2
(c) 1
+1
+ 22
+ 16
+ 37
74
69
38
51
(c) 20 =
Date: ___________________
Page 163: Number Sentences
163
Linkage
Number: Operations
Integration
English language: Comparing word sentences to number sentences; converting word problems to
number problems; breaking word problems into a series of number operations
Maths at home/parental involvement
Find uses of the words ‘minimum’ and ‘maximum’ in the world: Maximum weight, maximum
temperature, maximum speed, maximum size, maximum height, etc. Minimum wage,
minimum effort, minimum time, minimum speed, minimum price, etc.
Notes
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