Primary 1 maths · Operations · About 8 minutes
Recognise equal groups and multiplication within 40
Check one group, then check that the others match it before counting the total.
Start the interactive lesson →Open practice activity
What you will learn
- Recognise equal groups and multiplication within 40
Models used: number sentences, stories, diagrams.
Before you start
Count equal groups
Here is one plate with 4 biscuits.
There is 1 group, with 4 objects in each group. Count a group before counting them all.
Here is one plate with 4 biscuits.
Multiplication counts equal groups. Plates holding 3, 3, 2 and 3 cannot be read as 4 × 3, because one plate differs.
4 = 1 × 4 = 4
There are 2 groups, with 4 objects in each group. Count a group before counting them all.
A second plate has another 4. Both groups are the same size.
4 + 4 = 2 × 4 = 8
There are 3 groups, with 4 objects in each group. Count a group before counting them all.
With three plates, we have three groups of four.
4 + 4 + 4 = 12
4 + 4 + 4 = 3 × 4 = 12
3 rows run across the picture; each row contains 4 objects.
We can turn the arrangement into rows. Every biscuit is still here.
3 × 4 = 12
3 rows of 4 = 3 × 4 = 12
What did the picture help us see?
We can turn the arrangement into rows. Every biscuit is still here.
Worked example: A new example, together
What is 11 × 3?
11 rows of 3 = 11 × 3 = 33
11 rows run across the picture; each row contains 3 objects.
Check one group, then check that the others match it before counting the total.
Multiplying each part of a amount and joining the products preserves the total.
11 rows run across the picture; each row contains 3 objects.
Split 11 by place value: 10 + 1.
What is 11 × 3?
33
11 rows run across the picture; each row contains 3 objects.
Split 11 by place value: 10 + 1.
11 rows of 3 = 11 × 3 = 33
11 rows run across the picture; each row contains 3 objects.
10 × 3 = 30; 1 × 3 = 3.
11 rows of 3 = 11 × 3 = 33
11 rows run across the picture; each row contains 3 objects.
Join the products: 30 + 3 = 33.
11 rows of 3 = 11 × 3 = 33
11 rows run across the picture; each row contains 3 objects.
Check the result against the question we started with.
33 ÷ 3 = 11.
We found 33. Multiplying each part of a amount and joining the products preserves the total.
11 rows of 3 = 11 × 3 = 33
Common mistakes to discuss
- Groups that are not equal. Multiplication counts equal groups only. Four plates holding 3, 3, 2 and 3 cannot be read as 4 × 3.
Check your understanding
- Recognise equal groups and multiplication within 40
- recognise equal groups and record them as a multiplication
- check the answer against the original quantities and units
Explain your reasoning to an adult, then try a fresh question in the interactive lesson. A result from one attempt is not proof of lasting mastery.
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