New
New
Year 3

Use known facts to add and subtract multiples of 100 within 1000

I can add and subtract multiples of 100

New
New
Year 3

Use known facts to add and subtract multiples of 100 within 1000

I can add and subtract multiples of 100

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Lesson details

Key learning points

  1. Known facts can be used to help calculate with multiples of a hundred.
  2. If we know that 2 ones plus 4 ones equals 6 ones we know that 2 100s plus 4 100s equals 6 100s.
  3. Number facts to 10 can help us to add and subtract multiples of a hundred.

Keywords

  • Known facts - A known fact is something that you already know and can use to help you.

  • Multiple - A multiple is the result of multiplying a number by another whole number.

Common misconception

Pupils may find it difficult to connect calculating with hundreds with known facts.

Pupils need to be encouraged to 'unitise' hundreds to make calculation easier, seeing 500 as 5 lots of one hundred.

Pupils may need base ten blocks ('hundreds') to support their thinking and help them connect calculating with hundreds with known facts (e.g. 3 + 4 = 7 so 300 + 400 = 700). Number lines and bar models are also useful representations for pupils.
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).

Lesson video

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6 Questions

Q1.
What is 40 + 40?
8
16
44
Correct answer: 80
Q2.
100 − 40 =
Correct Answer: 60, sixty
Q3.
What is the sum of 30, 30 and 10?
60
Correct answer: 70
80
90
Q4.
What is the value of the missing part in the bar model?
An image in a quiz
Correct Answer: 20, twenty
Q5.
What is the missing number? + 10 = 120
Correct Answer: 110, one hundred and ten
Q6.
Which pair of numbers do not add up to equal 90?
30 + 60
40 + 50
70 + 20
Correct answer: 90 + 10

6 Questions

Q1.
Which of these numbers are multiples of a hundred?
Correct answer: 300
Correct answer: 500
650
Correct answer: 900
Q2.
Which known fact could you use to help you calculate 500 + 300?
5 + 2 = 7
Correct answer: 3 + 5 = 8
3 + 2 = 5
3 + 3 = 6
Q3.
What is 100 less than 600?
Correct Answer: 500, five hundred
Q4.
Which pairs of numbers are equal to 600?
Correct answer: 200 and 400
Correct answer: 300 and 300
500 and 200
Q5.
What is the value of the missing part in the bar model?
An image in a quiz
Correct Answer: 100, hundred, one hundred
Q6.
Which pairs of numbers could be used to complete the bar model?
An image in a quiz
100 and 700
Correct answer: 200 and 500
Correct answer: 300 and 400
Correct answer: 600 and 100