New
New
Add three addends efficiently using a range of strategies
I can choose the best strategy to add three small numbers together.
Lesson 5 of 10
New
New
- Year 3
Add three addends efficiently using a range of strategies
I can choose the best strategy to add three small numbers together.
Lesson details
Key learning points
- Using commutativity allows us to simplify a problem with three addends.
- Using known facts allows us to add three addends efficiently.
- Rearranging the addends to identify the pairs that total 10 allows us to add efficiently.
Keywords
Addend - A number added to another.
Commutative - Addition is commutative. This means the order of the addends can be changed without changing the calculation or sum.
Equation - An equation is used to show that one number or calculation is equal to another.
Sum - The total when numbers are added together.
Common misconception
Children rely on one strategy for adding to find a sum and do not consider the values.
Discuss when it is most efficient to use doubles, near doubles, number pairs to 10. Model efficient approaches.
This is a good opportunity to encourage pupils to think about efficiency. Representing problems concretely can allow pupils to explore different strategies such as summing doubles or near doubles.
Teacher tip
Licence
This content is © Oak National Academy Limited (2025), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.6 + 4 + 2 =
6 + 4 + 2 =
10
14
16
Q2.6 + 6 + 2 =
6 + 6 + 2 =
Q3.Match the equation to the sum.
Match the equation to the sum.
Q4.What is the sum of the numbers in the bar model?
What is the sum of the numbers in the bar model?
13
17
19
Q5.What addend is missing from the bar model?
What addend is missing from the bar model?
7
8
9
Q6.The missing numbers from this bar model both have the same value. What are both numbers?
The missing numbers from this bar model both have the same value. What are both numbers?
6
7
10
Assessment exit quiz
6 Questions
Q1.How would you find the sum of these calculations? Match them to the strategy you would use.
How would you find the sum of these calculations? Match them to the strategy you would use.
Q2.What is the sum of the numbers in the bar model?
What is the sum of the numbers in the bar model?
13
15
17
Q3.Match up the equations to the correct sum.
Match up the equations to the correct sum.
Q4.What is the missing addend in the bar model?
What is the missing addend in the bar model?
5
8
9
Q5.What is 8 + 3 + 8?
What is 8 + 3 + 8?
16
17
18
Q6.Which calculations could be used to make this equation correct?
Which calculations could be used to make this equation correct?
8 + 8 + 2
9 + 2 + 6
