Halve even 2-digit numbers and multiples of 10 | Maths

Starter quiz

Use the bar model to complete the sentence. Half of 6 is equal to ______

'3' ✓
If I know that half of 8 is equal to 4, then I know that _____________

double 4 is equal to 8 ✓

double 3 is equal to 6

double 2 is equal to 4
Which facts are represented by this bar model?

Double 3 is equal to 6

Double 5 is equal to 10 ✓

Half of 8 is equal to 4

Half of 10 is equal to 5 ✓
Which equation is represented by this bar model?

2 × 3 = 6

2 × 4 = 8 ✓

2 × 5 = 10
Alex had 10 marbles. He gave half to Jacob. How many marbles did Jacob get? ______ marbles

'5' ✓
Aisha gave half of her biscuits to Alex. Aisha was left with 7 biscuits. How many biscuits did Aisha have to begin with? ______ biscuits

'14' ✓

Exit quiz

Match the statements.

Double 3 is equal to 6

⇔

Half of 6 is equal to 3 ✓

Double 5 is equal to 10

⇔

Half of 10 is equal to 5 ✓

Double 6 is equal to 12

⇔

Half of 12 is equal to 6 ✓

Double 4 is equal to 8

⇔

Half of 8 is equal to 4 ✓
Which facts will help you to find half of 14 by partitioning the parts?

Half of 10 is equal to 5 ✓

Half of 8 is equal to 4

Half of 6 is equal to 3

Half of 4 is equal to 2 ✓
Match the known facts.

Half of 4 tens is 2 tens

⇔

Half of 40 is equal to 20 ✓

Half of 2 tens is 1 ten

⇔

Half of 20 is equal to 10 ✓

Half of 6 tens is 3 tens

⇔

Half of 60 is equal to 30 ✓

Half of 8 tens is 4 tens

⇔

Half of 80 is equal to 40 ✓
How can you find half of 28?

Find half of 2 tens and half of 8 ones ✓

Find half of 8 tens and half of 4 ones

Find half of 20 and half of 8 ✓

Find half of 80 and half of 4
Look at the image of Base 10 blocks. What is half of 24?

'12' ✓
Find half of 50 by partitioning. Half of 50 = ______

'25' ✓

Worksheet

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Lesson Details

Key learning points

Halving facts to 10 can help to halve 2-digit numbers.
To halve 2-digit numbers, partition the 2-digit number, halve the tens and the ones, then recombine.

Common misconception

Incorrectly partitioning and halving odd multiples of 10

Ensure children use representations where they are able to see the partitioning of the number into an even multiple of 10 and 10 more. That way, they can clearly see they are still finding half of 30 for example.

Keywords

Double / doubling - To become twice as many / to multiply by two.
Half / halving - One of two equal parts of a whole. To divide into two equal parts.
Partition - The act of splitting an object or value down into smaller parts.