Step-by-step Maths Level 3: Adding two 2-digit numbers with carrying

Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.

1. Write the numbers in columns. Keep the ones under the ones and the tens under the tens.
   72 over 30
2. Add the ones. The ones make less than 10, so no ten is carried.
   2 + 0 = 2
3. Add the tens. There is no carried ten to add. The tens make 10 or more, so write the tens digit and carry 1 hundred.
   7 + 3 = 10
4. Add the hundreds. Add any carried hundred too.
   0 + 0 + 1 carried = 1
5. Write the answer. Read the columns from left to right.
   102

Check. Check: 102 - 30 = 72.

Watch out. When the tens make 10 or more, carry a hundred to the hundreds column.

Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.

1. Write the numbers in columns. Keep the ones under the ones and the tens under the tens.
   92 over 57
2. Add the ones. The ones make less than 10, so no ten is carried.
   2 + 7 = 9
3. Add the tens. There is no carried ten to add. The tens make 10 or more, so write the tens digit and carry 1 hundred.
   9 + 5 = 14
4. Add the hundreds. Add any carried hundred too.
   0 + 0 + 1 carried = 1
5. Write the answer. Read the columns from left to right.
   149

Check. Check: 149 - 57 = 92.

Watch out. When the tens make 10 or more, carry a hundred to the hundreds column.

Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.

1. Write the numbers in columns. Keep the ones under the ones and the tens under the tens.
   44 over 70
2. Add the ones. The ones make less than 10, so no ten is carried.
   4 + 0 = 4
3. Add the tens. There is no carried ten to add. The tens make 10 or more, so write the tens digit and carry 1 hundred.
   4 + 7 = 11
4. Add the hundreds. Add any carried hundred too.
   0 + 0 + 1 carried = 1
5. Write the answer. Read the columns from left to right.
   114

Check. Check: 114 - 70 = 44.

Watch out. When the tens make 10 or more, carry a hundred to the hundreds column.

Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.

1. Write the numbers in columns. Keep the ones under the ones and the tens under the tens.
   79 over 43
2. Add the ones. The ones make 10 or more, so write the ones digit and carry 1 ten.
   9 + 3 = 12, write 2 and carry 1
3. Add the tens. Add the carried ten with the tens. The tens make 10 or more, so write the tens digit and carry 1 hundred.
   7 + 4 + 1 carried = 12
4. Add the hundreds. Add any carried hundred too.
   0 + 0 + 1 carried = 1
5. Write the answer. Read the columns from left to right.
   122

Check. Check: 122 - 43 = 79.

Watch out. When the tens make 10 or more, carry a hundred to the hundreds column.

Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.

1. Write the numbers in columns. Keep the ones under the ones and the tens under the tens.
   82 over 90
2. Add the ones. The ones make less than 10, so no ten is carried.
   2 + 0 = 2
3. Add the tens. There is no carried ten to add. The tens make 10 or more, so write the tens digit and carry 1 hundred.
   8 + 9 = 17
4. Add the hundreds. Add any carried hundred too.
   0 + 0 + 1 carried = 1
5. Write the answer. Read the columns from left to right.
   172

Check. Check: 172 - 90 = 82.

Watch out. When the tens make 10 or more, carry a hundred to the hundreds column.

Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.

1. Write the numbers in columns. Keep the ones under the ones and the tens under the tens.
   73 over 70
2. Add the ones. The ones make less than 10, so no ten is carried.
   3 + 0 = 3
3. Add the tens. There is no carried ten to add. The tens make 10 or more, so write the tens digit and carry 1 hundred.
   7 + 7 = 14
4. Add the hundreds. Add any carried hundred too.
   0 + 0 + 1 carried = 1
5. Write the answer. Read the columns from left to right.
   143

Check. Check: 143 - 70 = 73.

Watch out. When the tens make 10 or more, carry a hundred to the hundreds column.

Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.

1. Write the numbers in columns. Keep the ones under the ones and the tens under the tens.
   97 over 65
2. Add the ones. The ones make 10 or more, so write the ones digit and carry 1 ten.
   7 + 5 = 12, write 2 and carry 1
3. Add the tens. Add the carried ten with the tens. The tens make 10 or more, so write the tens digit and carry 1 hundred.
   9 + 6 + 1 carried = 16
4. Add the hundreds. Add any carried hundred too.
   0 + 0 + 1 carried = 1
5. Write the answer. Read the columns from left to right.
   162

Check. Check: 162 - 65 = 97.

Watch out. When the tens make 10 or more, carry a hundred to the hundreds column.

Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.

1. Write the numbers in columns. Keep the ones under the ones and the tens under the tens.
   83 over 87
2. Add the ones. The ones make 10 or more, so write the ones digit and carry 1 ten.
   3 + 7 = 10, write 0 and carry 1
3. Add the tens. Add the carried ten with the tens. The tens make 10 or more, so write the tens digit and carry 1 hundred.
   8 + 8 + 1 carried = 17
4. Add the hundreds. Add any carried hundred too.
   0 + 0 + 1 carried = 1
5. Write the answer. Read the columns from left to right.
   170

Check. Check: 170 - 87 = 83.

Watch out. When the tens make 10 or more, carry a hundred to the hundreds column.

Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.

1. Write the numbers in columns. Keep the ones under the ones and the tens under the tens.
   60 over 77
2. Add the ones. The ones make less than 10, so no ten is carried.
   0 + 7 = 7
3. Add the tens. There is no carried ten to add. The tens make 10 or more, so write the tens digit and carry 1 hundred.
   6 + 7 = 13
4. Add the hundreds. Add any carried hundred too.
   0 + 0 + 1 carried = 1
5. Write the answer. Read the columns from left to right.
   137

Check. Check: 137 - 77 = 60.

Watch out. When the tens make 10 or more, carry a hundred to the hundreds column.

Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.

1. Write the numbers in columns. Keep the ones under the ones and the tens under the tens.
   48 over 14
2. Add the ones. The ones make 10 or more, so write the ones digit and carry 1 ten.
   8 + 4 = 12, write 2 and carry 1
3. Add the tens. Add the carried ten with the tens.
   4 + 1 + 1 carried = 6
4. Write the answer. Read the columns from left to right.
   62

Check. Check: 62 - 14 = 48.

Watch out. When the ones make 10 or more, carry a ten to the tens column. Do not forget it.

Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.

1. Write the numbers in columns. Keep the ones under the ones and the tens under the tens.
   89 over 83
2. Add the ones. The ones make 10 or more, so write the ones digit and carry 1 ten.
   9 + 3 = 12, write 2 and carry 1
3. Add the tens. Add the carried ten with the tens. The tens make 10 or more, so write the tens digit and carry 1 hundred.
   8 + 8 + 1 carried = 17
4. Add the hundreds. Add any carried hundred too.
   0 + 0 + 1 carried = 1
5. Write the answer. Read the columns from left to right.
   172

Check. Check: 172 - 83 = 89.

Watch out. When the tens make 10 or more, carry a hundred to the hundreds column.

Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.

1. Write the numbers in columns. Keep the ones under the ones and the tens under the tens.
   44 over 91
2. Add the ones. The ones make less than 10, so no ten is carried.
   4 + 1 = 5
3. Add the tens. There is no carried ten to add. The tens make 10 or more, so write the tens digit and carry 1 hundred.
   4 + 9 = 13
4. Add the hundreds. Add any carried hundred too.
   0 + 0 + 1 carried = 1
5. Write the answer. Read the columns from left to right.
   135

Check. Check: 135 - 91 = 44.

Watch out. When the tens make 10 or more, carry a hundred to the hundreds column.

Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.

1. Write the numbers in columns. Keep the ones under the ones and the tens under the tens.
   88 over 48
2. Add the ones. The ones make 10 or more, so write the ones digit and carry 1 ten.
   8 + 8 = 16, write 6 and carry 1
3. Add the tens. Add the carried ten with the tens. The tens make 10 or more, so write the tens digit and carry 1 hundred.
   8 + 4 + 1 carried = 13
4. Add the hundreds. Add any carried hundred too.
   0 + 0 + 1 carried = 1
5. Write the answer. Read the columns from left to right.
   136

Check. Check: 136 - 48 = 88.

Watch out. When the tens make 10 or more, carry a hundred to the hundreds column.

Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.

1. Write the numbers in columns. Keep the ones under the ones and the tens under the tens.
   80 over 94
2. Add the ones. The ones make less than 10, so no ten is carried.
   0 + 4 = 4
3. Add the tens. There is no carried ten to add. The tens make 10 or more, so write the tens digit and carry 1 hundred.
   8 + 9 = 17
4. Add the hundreds. Add any carried hundred too.
   0 + 0 + 1 carried = 1
5. Write the answer. Read the columns from left to right.
   174

Check. Check: 174 - 94 = 80.

Watch out. When the tens make 10 or more, carry a hundred to the hundreds column.

Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.

1. Write the numbers in columns. Keep the ones under the ones and the tens under the tens.
   57 over 75
2. Add the ones. The ones make 10 or more, so write the ones digit and carry 1 ten.
   7 + 5 = 12, write 2 and carry 1
3. Add the tens. Add the carried ten with the tens. The tens make 10 or more, so write the tens digit and carry 1 hundred.
   5 + 7 + 1 carried = 13
4. Add the hundreds. Add any carried hundred too.
   0 + 0 + 1 carried = 1
5. Write the answer. Read the columns from left to right.
   132

Check. Check: 132 - 75 = 57.

Watch out. When the tens make 10 or more, carry a hundred to the hundreds column.

Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.

1. Write the numbers in columns. Keep the ones under the ones and the tens under the tens.
   87 over 51
2. Add the ones. The ones make less than 10, so no ten is carried.
   7 + 1 = 8
3. Add the tens. There is no carried ten to add. The tens make 10 or more, so write the tens digit and carry 1 hundred.
   8 + 5 = 13
4. Add the hundreds. Add any carried hundred too.
   0 + 0 + 1 carried = 1
5. Write the answer. Read the columns from left to right.
   138

Check. Check: 138 - 51 = 87.

Watch out. When the tens make 10 or more, carry a hundred to the hundreds column.