Use knowledge of doubles to calculate near-doubles | Maths

Starter quiz

When we add two equal addends, we are ______
- doubling ✓
- halving
What number would complete this bar model?
- '2' ✓
Tick all the correct statements.
- Half of 8 is 4 ✓
- Half of 4 is 2 ✓
- Double 4 is 2
- Double 2 is 4 ✓
What is the missing number? Half of ______ is 3
- 8
- 7
- 6 ✓
- 5
Who is correct?
- Sam
- Jacob ✓
Sam is 8 years old. She is double the age of her brother. How old is her brother?
- 3 years old
- 4 years old ✓
- 1 years old
- 2 years old

Exit quiz

What near double is the representation showing?
- 6 + 5
- 5 + 5 ✓
- 5 + 4
What near double is the representation showing?
- 3 + 3 ✓
- 3 + 4
- 4 + 5
Which of these double facts would help to solve this near-double problem? 2 + 3 =
- 1 + 1
- 2 + 2 ✓
- 3 + 3 ✓
- 5 + 5
Finish the sentence. Near doubles always have ______
- two odd addends.
- two even addends.
- one odd and one even addend. ✓
What is the missing number in this bar model?
- 4 ✓
- 3
- 2
- 5
Jacob ran 4 laps of the track. Then he ran another 3 laps. How many laps did he run in total?
- '7' ✓

Worksheet

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Presentation

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Lesson Details

Key learning points

Knowing double facts helps you to calculate near-doubles.
If 2 + 2 is equal to 4, then 2 + 3 is equal to one more than 4 which is 5

Common misconception

Children could try to apply this idea to other near-double facts that may be more easily solved using other strategies.

0 + 1 and 1 + 2 are near-doubles, but these are more easily solved using the 'one more'/ 'one less' strategy. Explore this together before leading children to the most efficient strategy for calculating.

Keywords

Double - To become twice as many.
Near-double - A near-double is a number close to a double.
Addends - Any of the numbers that are added together.