New
New
Year 2
Explain how doubling and halving are related
I can explain how doubling and halving are related.
New
New
Year 2
Explain how doubling and halving are related
I can explain how doubling and halving are related.
Lesson details
Key learning points
- If double 4 is 8, then half of 8 is 4
- Halving means to partition the number into two equal groups.
- Halving is the inverse of doubling.
- Whether doubling or halving, we can also see these as our 2 times tables facts.
Common misconception
Children may inaccurately recall related doubling facts to solve halving problems.
Represent each problem as a bar model (as the whole and two equal parts) before solving. Encourage children to check that the two equal parts are equal to the whole.
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.
Use the stem sentence, 'If I know ..., then I know ...' to help children see how doubling facts can help solve halving problems. Ensure children are encouraged to use this stem sentence when talking through their approach to a problem.
Teacher tip
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Video
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Starter quiz
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6 Questions
Q1.
Which double is being shown here?
Double 4
Double 5
Q2.
Double 3 tens is ___
6
16
Q3.
Double 12 is
Q4.
Double 40 is
Q5.
Which of these equations could I use doubling knowledge to solve?
4 + 2 = ?
Q6.
What is 14 × 2 = ?
Exit quiz
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6 Questions
Q1.
Use the bar model to complete the sentence. Half of 8 is equal to
Q2.
If I know that half of 6 is equal to 3, then I know that _____________
double 4 is equal to 8
double 2 is equal to 4
Q3.
Which facts are represented by this bar model?
Double 4 is equal to 8
Half of 6 is equal to 3
Q4.
Which equation is represented by this bar model?
2 × 3 = 6
2 × 4 = 8
Q5.
Alex had 4 marbles. He gave half to Jacob. How many marbles did Jacob get? marbles
Q6.
Aisha gave half of her biscuits to Alex. Aisha was left with 6 biscuits. How many biscuits did Aisha have to begin with? biscuits