Problem solving with EYFS, Key Stage 1 and Key Stage 2 children ...

The National Strategies | Primary
Problem solving with EYFS, Key Stage 1 and Key Stage 2 children:
Logic problems and puzzles
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Main teaching activity
Remind children that in the previous lesson we used shapes to stand for mystery numbers.
Write the following problem on the board:
I have 20 apples. Six apples are red. How many are green?
Q. Could we write this in a number sentence? Could we use symbols or shapes to help?
Ask children to discuss this in pairs and record their number sentences on their whiteboards.
Ask a child who has used a symbol or empty box to explain the recording.
6 + = 20
6 + 14 = 20
I had 14 green apples.
If no one used empty boxes ask a child to explain how they worked it out and model this using the
empty box number sentences.
This work is providing children with one strategy to solve the lesson’s
main problem.
Write the following problem on the board. Ask children to work in pairs and to record a number
sentence.
I have 16 pens. Some are red and some are blue.
I have 9 red pens. How many blue pens are there?
Ask a child who recorded using an empty box to share this with the class.
9 + = 16
9 + 7 = 16
I had 7 blue pens.
Write the following problem on the board. Ask children to discuss how they might work this out.
Are more children able to write this as an empty box problem?
I have 24 cars. Some are large and some are small.
I have an equal number of large and small cars.
How many large cars are there?
Q. Which word in the problem is a key piece of information?
Agree that the word ‘equal’ was the key word and this means that the number of large cars is the same as
the number of small cars. Ask children if they can record this as a number sentence.
+ = 24
Q. How can we work out what is?
Agree that we can halve 24.
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