Step-by-step Maths Level 2: Subtracting two 2-digit numbers
Part of the Step-by-step Maths Level 2 adding and subtracting within 100 chapter. Chapter overview · whole chapter on one page
Subtracting two 2-digit numbers
To subtract, take the tens away from the tens and the ones away from the ones.
In this step, you never need to change a ten for ones, so each part can be taken away directly.
Key ideas
- Take the tens away from the tens.
- Take the ones away from the ones.
- Put the two answers together.
Method. Take away the tens, then take away the ones. Put the two answers together.
- Take away the tens: 6 tens - 2 tens. We take the tens from the tens.6 - 2 = 4 tens, which is 40
- Take away the ones: 8 - 3. We take the ones from the ones.8 - 3 = 5
- Put them together: 40 + 5. The tens and the ones make the answer.40 + 5 = 45
- Write the answer. 45
Check. Add back: 45 + 23 = 68. It is right.
Watch out. Take the ones from the ones and the tens from the tens. Do not take the ones from the tens.
Method. Take away the tens, then take away the ones. Put the two answers together.
- Take away the tens: 9 tens - 4 tens. We take the tens from the tens.9 - 4 = 5 tens, which is 50
- Take away the ones: 7 - 5. We take the ones from the ones.7 - 5 = 2
- Put them together: 50 + 2. The tens and the ones make the answer.50 + 2 = 52
- Write the answer. 52
Check. Add back: 52 + 45 = 97. It is right.
Watch out. Take the ones from the ones and the tens from the tens. Do not take the ones from the tens.
Method. Take away the tens, then take away the ones. Put the two answers together.
- Take away the tens: 8 tens - 3 tens. We take the tens from the tens.8 - 3 = 5 tens, which is 50
- Take away the ones: 6 - 1. We take the ones from the ones.6 - 1 = 5
- Put them together: 50 + 5. The tens and the ones make the answer.50 + 5 = 55
- Write the answer. 55
Check. Add back: 55 + 31 = 86. It is right.
Watch out. Take the ones from the ones and the tens from the tens. Do not take the ones from the tens.
Watch out
Watch out. 68 - 23 is 45. Take 2 tens from 6 tens, and 3 ones from 8 ones.
Exam tip
Grown-up tip. Use tens sticks and ones cubes. Take away the sticks first, then the cubes.
Exercise 7D Practice: subtracting two 2-digit numbers
Non-calculatorMethod. Take away the tens, then take away the ones. Put the two answers together.
- Take away the tens: 8 tens - 5 tens. We take the tens from the tens.8 - 5 = 3 tens, which is 30
- Take away the ones: 5 - 4. We take the ones from the ones.5 - 4 = 1
- Put them together: 30 + 1. The tens and the ones make the answer.30 + 1 = 31
- Write the answer. 31
Check. Add back: 31 + 54 = 85. It is right.
Watch out. Take the ones from the ones and the tens from the tens. Do not take the ones from the tens.
Method. Take away the tens, then take away the ones. Put the two answers together.
- Take away the tens: 9 tens - 8 tens. We take the tens from the tens.9 - 8 = 1 tens, which is 10
- Take away the ones: 8 - 8. We take the ones from the ones.8 - 8 = 0
- Put them together: 10 + 0. The tens and the ones make the answer.10 + 0 = 10
- Write the answer. 10
Check. Add back: 10 + 88 = 98. It is right.
Watch out. Take the ones from the ones and the tens from the tens. Do not take the ones from the tens.
Method. Take away the tens, then take away the ones. Put the two answers together.
- Take away the tens: 9 tens - 6 tens. We take the tens from the tens.9 - 6 = 3 tens, which is 30
- Take away the ones: 5 - 5. We take the ones from the ones.5 - 5 = 0
- Put them together: 30 + 0. The tens and the ones make the answer.30 + 0 = 30
- Write the answer. 30
Check. Add back: 30 + 65 = 95. It is right.
Watch out. Take the ones from the ones and the tens from the tens. Do not take the ones from the tens.
Method. Take away the tens, then take away the ones. Put the two answers together.
- Take away the tens: 7 tens - 6 tens. We take the tens from the tens.7 - 6 = 1 tens, which is 10
- Take away the ones: 7 - 2. We take the ones from the ones.7 - 2 = 5
- Put them together: 10 + 5. The tens and the ones make the answer.10 + 5 = 15
- Write the answer. 15
Check. Add back: 15 + 62 = 77. It is right.
Watch out. Take the ones from the ones and the tens from the tens. Do not take the ones from the tens.
Method. Take away the tens, then take away the ones. Put the two answers together.
- Take away the tens: 6 tens - 4 tens. We take the tens from the tens.6 - 4 = 2 tens, which is 20
- Take away the ones: 5 - 2. We take the ones from the ones.5 - 2 = 3
- Put them together: 20 + 3. The tens and the ones make the answer.20 + 3 = 23
- Write the answer. 23
Check. Add back: 23 + 42 = 65. It is right.
Watch out. Take the ones from the ones and the tens from the tens. Do not take the ones from the tens.
Method. Take away the tens, then take away the ones. Put the two answers together.
- Take away the tens: 9 tens - 8 tens. We take the tens from the tens.9 - 8 = 1 tens, which is 10
- Take away the ones: 9 - 1. We take the ones from the ones.9 - 1 = 8
- Put them together: 10 + 8. The tens and the ones make the answer.10 + 8 = 18
- Write the answer. 18
Check. Add back: 18 + 81 = 99. It is right.
Watch out. Take the ones from the ones and the tens from the tens. Do not take the ones from the tens.
Method. Take away the tens, then take away the ones. Put the two answers together.
- Take away the tens: 8 tens - 1 tens. We take the tens from the tens.8 - 1 = 7 tens, which is 70
- Take away the ones: 6 - 4. We take the ones from the ones.6 - 4 = 2
- Put them together: 70 + 2. The tens and the ones make the answer.70 + 2 = 72
- Write the answer. 72
Check. Add back: 72 + 14 = 86. It is right.
Watch out. Take the ones from the ones and the tens from the tens. Do not take the ones from the tens.
Method. Take away the tens, then take away the ones. Put the two answers together.
- Take away the tens: 9 tens - 4 tens. We take the tens from the tens.9 - 4 = 5 tens, which is 50
- Take away the ones: 4 - 0. We take the ones from the ones.4 - 0 = 4
- Put them together: 50 + 4. The tens and the ones make the answer.50 + 4 = 54
- Write the answer. 54
Check. Add back: 54 + 40 = 94. It is right.
Watch out. Take the ones from the ones and the tens from the tens. Do not take the ones from the tens.
Method. Take away the tens, then take away the ones. Put the two answers together.
- Take away the tens: 3 tens - 2 tens. We take the tens from the tens.3 - 2 = 1 tens, which is 10
- Take away the ones: 7 - 3. We take the ones from the ones.7 - 3 = 4
- Put them together: 10 + 4. The tens and the ones make the answer.10 + 4 = 14
- Write the answer. 14
Check. Add back: 14 + 23 = 37. It is right.
Watch out. Take the ones from the ones and the tens from the tens. Do not take the ones from the tens.
Method. Take away the tens, then take away the ones. Put the two answers together.
- Take away the tens: 9 tens - 7 tens. We take the tens from the tens.9 - 7 = 2 tens, which is 20
- Take away the ones: 8 - 3. We take the ones from the ones.8 - 3 = 5
- Put them together: 20 + 5. The tens and the ones make the answer.20 + 5 = 25
- Write the answer. 25
Check. Add back: 25 + 73 = 98. It is right.
Watch out. Take the ones from the ones and the tens from the tens. Do not take the ones from the tens.
Method. Take away the tens, then take away the ones. Put the two answers together.
- Take away the tens: 7 tens - 3 tens. We take the tens from the tens.7 - 3 = 4 tens, which is 40
- Take away the ones: 9 - 4. We take the ones from the ones.9 - 4 = 5
- Put them together: 40 + 5. The tens and the ones make the answer.40 + 5 = 45
- Write the answer. 45
Check. Add back: 45 + 34 = 79. It is right.
Watch out. Take the ones from the ones and the tens from the tens. Do not take the ones from the tens.
Method. Take away the tens, then take away the ones. Put the two answers together.
- Take away the tens: 7 tens - 2 tens. We take the tens from the tens.7 - 2 = 5 tens, which is 50
- Take away the ones: 3 - 2. We take the ones from the ones.3 - 2 = 1
- Put them together: 50 + 1. The tens and the ones make the answer.50 + 1 = 51
- Write the answer. 51
Check. Add back: 51 + 22 = 73. It is right.
Watch out. Take the ones from the ones and the tens from the tens. Do not take the ones from the tens.
Method. Take away the tens, then take away the ones. Put the two answers together.
- Take away the tens: 9 tens - 7 tens. We take the tens from the tens.9 - 7 = 2 tens, which is 20
- Take away the ones: 8 - 6. We take the ones from the ones.8 - 6 = 2
- Put them together: 20 + 2. The tens and the ones make the answer.20 + 2 = 22
- Write the answer. 22
Check. Add back: 22 + 76 = 98. It is right.
Watch out. Take the ones from the ones and the tens from the tens. Do not take the ones from the tens.
Method. Take away the tens, then take away the ones. Put the two answers together.
- Take away the tens: 9 tens - 8 tens. We take the tens from the tens.9 - 8 = 1 tens, which is 10
- Take away the ones: 9 - 8. We take the ones from the ones.9 - 8 = 1
- Put them together: 10 + 1. The tens and the ones make the answer.10 + 1 = 11
- Write the answer. 11
Check. Add back: 11 + 88 = 99. It is right.
Watch out. Take the ones from the ones and the tens from the tens. Do not take the ones from the tens.
Method. Take away the tens, then take away the ones. Put the two answers together.
- Take away the tens: 4 tens - 2 tens. We take the tens from the tens.4 - 2 = 2 tens, which is 20
- Take away the ones: 9 - 8. We take the ones from the ones.9 - 8 = 1
- Put them together: 20 + 1. The tens and the ones make the answer.20 + 1 = 21
- Write the answer. 21
Check. Add back: 21 + 28 = 49. It is right.
Watch out. Take the ones from the ones and the tens from the tens. Do not take the ones from the tens.
Method. Take away the tens, then take away the ones. Put the two answers together.
- Take away the tens: 8 tens - 7 tens. We take the tens from the tens.8 - 7 = 1 tens, which is 10
- Take away the ones: 9 - 8. We take the ones from the ones.9 - 8 = 1
- Put them together: 10 + 1. The tens and the ones make the answer.10 + 1 = 11
- Write the answer. 11
Check. Add back: 11 + 78 = 89. It is right.
Watch out. Take the ones from the ones and the tens from the tens. Do not take the ones from the tens.