 # KS1 Maths Quiz - Year 2 Calculation - Addition and Subtraction Facts to 100 (Questions)

This quiz addresses the requirements of the National Curriculum KS1 Maths and Numeracy for children aged 6 and 7 in year 2. Specifically this quiz is aimed at the section dealing with knowing number facts to 100.

Knowing addition and subtraction facts by heart means being able to quickly know the pairs of numbers which make a total of 100, as well as the associated subtraction facts. This knowledge of the number pairs, or bonds, to 100 can be linked to knowing the number pairs to 10. For example, if you know that 3 + 7 = 10, then you may realise that 30 + 70 = 100.

1. If you know that 2 + 8 = 10, what else do you know?
 [ ] 20 + 80 = 100 [ ] 12 + 18 = 20 [ ] 2 + 80 = 100 [ ] 8 + 20 = 100
2. Which of the following is true?
 [ ] 6 + 4 = 10, so 60 + 4 = 100 [ ] 6 + 4 = 10, so 60 + 40 = 100 [ ] 6 + 4 = 10, so 16 + 14 = 100 [ ] 6 + 4 = 10, so 6 + 40 = 100
3. Which of these three other facts go with 30 + 70 = 100?
 [ ] 100 + 30 = 70 70 - 30 = 100 30 - 70 = 100 [ ] 30 + 30 = 70 70 - 30 = 100 30 - 100 = 70 [ ] 70 + 70 = 100 30 +30 = 100 100 - 100 = 30 [ ] 70 + 30 = 100 100 - 30 = 70 100 - 70 = 30
4. Which number is missing: 10 + ? = 100
 [ ] 100 [ ] 9 [ ] 90 [ ] 10
5. Which number fact is incorrect?
 [ ] 6 + 40 = 100 [ ] 60 + 40 = 100 [ ] 40 + 60 = 100 [ ] 100 - 60 = 40
6. Which three pairs of numbers all add up to 100?
 [ ] 20 + 80 10 + 90 50 + 50 [ ] 10 + 80 20 + 18 60 + 4 [ ] 12 + 18 20 + 8 100 + 10 [ ] 40 + 6 50 + 5 10 + 9
7. Which of the following is true?
 [ ] 10 - 80 = 20 [ ] 100 - 20 = 80 [ ] 80 - 20 = 100 [ ] 20 - 80 = 100
8. Which one of the following number pairs do not add up to give 100?
 [ ] 100 + 0 [ ] 90 + 10 [ ] 60 + 40 [ ] 20 + 18
9. Which 'family' of facts is incorrect?
 [ ] 10 + 90 = 100 90 + 10 = 100 100 - 90 = 10 100 - 10 = 90 [ ] 20 + 80 = 100 80 + 20 = 100 100 - 20 = 80 100 - 80 = 20 [ ] 60 + 50 = 100 50 + 60 = 100 100 - 60 = 50 100 - 50 = 60 [ ] 30 + 70 = 100 70 + 30 = 100 100 - 30 = 70 100 - 70 = 30
10. Which 'family' of facts is incorrect?
 [ ] 35 + 65 = 100 65 + 35 = 100 100 - 35 = 65 100 - 65 = 35 [ ] 25 + 75 = 100 75 + 25 = 100 100 - 25 = 75 100 - 75 = 25 [ ] 15 + 85 = 100 85 + 15 = 100 100 - 85 = 15 100 - 15 = 85 [ ] 65 + 45 = 100 45 + 65 = 100 100 - 65 = 45 100 - 45 = 65 KS1 Maths Quiz - Year 2 Calculation - Addition and Subtraction Facts to 100 (Answers)
1. If you know that 2 + 8 = 10, what else do you know?
 [x] 20 + 80 = 100 [ ] 12 + 18 = 20 [ ] 2 + 80 = 100 [ ] 8 + 20 = 100
80 + 20 would also give 100
2. Which of the following is true?
 [ ] 6 + 4 = 10, so 60 + 4 = 100 [x] 6 + 4 = 10, so 60 + 40 = 100 [ ] 6 + 4 = 10, so 16 + 14 = 100 [ ] 6 + 4 = 10, so 6 + 40 = 100
60 + 40 gives an answer which is ten times bigger than 6 + 4
3. Which of these three other facts go with 30 + 70 = 100?
 [ ] 100 + 30 = 70 70 - 30 = 100 30 - 70 = 100 [ ] 30 + 30 = 70 70 - 30 = 100 30 - 100 = 70 [ ] 70 + 70 = 100 30 +30 = 100 100 - 100 = 30 [x] 70 + 30 = 100 100 - 30 = 70 100 - 70 = 30
For the subtraction facts, the largest number should be at the beginning
4. Which number is missing: 10 + ? = 100
 [ ] 100 [ ] 9 [x] 90 [ ] 10
10 + 90 = 100, so 90 + 10 = 100 also
5. Which number fact is incorrect?
 [x] 6 + 40 = 100 [ ] 60 + 40 = 100 [ ] 40 + 60 = 100 [ ] 100 - 60 = 40
6 + 40 = 46!
6. Which three pairs of numbers all add up to 100?
 [x] 20 + 80 10 + 90 50 + 50 [ ] 10 + 80 20 + 18 60 + 4 [ ] 12 + 18 20 + 8 100 + 10 [ ] 40 + 6 50 + 5 10 + 9
All the others give different totals
7. Which of the following is true?
 [ ] 10 - 80 = 20 [x] 100 - 20 = 80 [ ] 80 - 20 = 100 [ ] 20 - 80 = 100
100 - 80 = 20 is the other subtraction fact for these numbers
8. Which one of the following number pairs do not add up to give 100?
 [ ] 100 + 0 [ ] 90 + 10 [ ] 60 + 40 [x] 20 + 18
20 + 18 = 38
9. Which 'family' of facts is incorrect?
 [ ] 10 + 90 = 100 90 + 10 = 100 100 - 90 = 10 100 - 10 = 90 [ ] 20 + 80 = 100 80 + 20 = 100 100 - 20 = 80 100 - 80 = 20 [x] 60 + 50 = 100 50 + 60 = 100 100 - 60 = 50 100 - 50 = 60 [ ] 30 + 70 = 100 70 + 30 = 100 100 - 30 = 70 100 - 70 = 30
60 + 50 = 110, so all the other facts must be incorrect too
10. Which 'family' of facts is incorrect?
 [ ] 35 + 65 = 100 65 + 35 = 100 100 - 35 = 65 100 - 65 = 35 [ ] 25 + 75 = 100 75 + 25 = 100 100 - 25 = 75 100 - 75 = 25 [ ] 15 + 85 = 100 85 + 15 = 100 100 - 85 = 15 100 - 15 = 85 [x] 65 + 45 = 100 45 + 65 = 100 100 - 65 = 45 100 - 45 = 65
65 + 45 = 110, so all the other facts must be incorrect too