Step-by-step Maths Level 3: Word problems, adding in any order, and estimating
Part of the Step-by-step Maths Level 3 adding within 1000 chapter. Chapter overview · whole chapter on one page
Word problems, adding in any order, and estimating
Read the problem and find the word that tells you to add. Words like altogether, more and in all mean add.
An estimate tells you roughly what the answer should be. Round the numbers, add them, then check the exact answer is close.
Key ideas
- Words like altogether and more mean add.
- Adding in any order gives the same total.
- An estimate should be close to the exact answer.
Method. Find the operation, then work out the total.
- Find the operation. We are putting two amounts together, so we add.178 + 56
- Work out the total. Use column addition with the ones first.178 + 56 = 234
- Write the answer. This is the total in the question.234
Check. Check: 234 - 56 = 178.
Watch out. Look for words like more, altogether and in all. These mean add.
Method. Find the operation, then work out the total.
- Find the operation. We are putting two amounts together, so we add.246 + 97
- Work out the total. Use column addition with the ones first.246 + 97 = 343
- Write the answer. This is the total in the question.343
Check. Check: 343 - 97 = 246.
Watch out. Look for words like more, altogether and in all. These mean add.
Method. Find the operation, then work out the total.
- Find the operation. We are putting two amounts together, so we add.312 + 79
- Work out the total. Use column addition with the ones first.312 + 79 = 391
- Write the answer. This is the total in the question.391
Check. Check: 391 - 79 = 312.
Watch out. Look for words like more, altogether and in all. These mean add.
Watch out
Watch out. Check that your answer is close to the estimate. If it is not, check the carrying.
Exam tip
Grown-up tip. Ask: “Is the answer about the right size? Did you carry the ten?”
Exercise 4D Practice: word problems and estimates
Non-calculatorMethod. Find the operation, then work out the total.
- Find the operation. We are putting two amounts together, so we add.457 + 194
- Work out the total. Use column addition with the ones first.457 + 194 = 651
- Write the answer. This is the total in the question.651
Check. Check: 651 - 194 = 457.
Watch out. Look for words like more, altogether and in all. These mean add.
Method. Find the operation, then work out the total.
- Find the operation. We are putting two amounts together, so we add.32 + 171
- Work out the total. Use column addition with the ones first.32 + 171 = 203
- Write the answer. This is the total in the question.203
Check. Check: 203 - 171 = 32.
Watch out. Look for words like more, altogether and in all. These mean add.
Method. Find the operation, then work out the total.
- Find the operation. We are putting two amounts together, so we add.427 + 16
- Work out the total. Use column addition with the ones first.427 + 16 = 443
- Write the answer. This is the total in the question.443
Check. Check: 443 - 16 = 427.
Watch out. Look for words like more, altogether and in all. These mean add.
Method. Find the operation, then work out the total.
- Find the operation. We are putting two amounts together, so we add.592 + 358
- Work out the total. Use column addition with the ones first.592 + 358 = 950
- Write the answer. This is the total in the question.950
Check. Check: 950 - 358 = 592.
Watch out. Look for words like more, altogether and in all. These mean add.
Method. Find the operation, then work out the total.
- Find the operation. We are putting two amounts together, so we add.336 + 177
- Work out the total. Use column addition with the ones first.336 + 177 = 513
- Write the answer. This is the total in the question.513
Check. Check: 513 - 177 = 336.
Watch out. Look for words like more, altogether and in all. These mean add.
Method. Find the operation, then work out the total.
- Find the operation. We are putting two amounts together, so we add.215 + 49
- Work out the total. Use column addition with the ones first.215 + 49 = 264
- Write the answer. This is the total in the question.264
Check. Check: 264 - 49 = 215.
Watch out. Look for words like more, altogether and in all. These mean add.
Method. Find the operation, then work out the total.
- Find the operation. We are putting two amounts together, so we add.348 + 98
- Work out the total. Use column addition with the ones first.348 + 98 = 446
- Write the answer. This is the total in the question.446
Check. Check: 446 - 98 = 348.
Watch out. Look for words like more, altogether and in all. These mean add.
Method. Find the operation, then work out the total.
- Find the operation. We are putting two amounts together, so we add.555 + 356
- Work out the total. Use column addition with the ones first.555 + 356 = 911
- Write the answer. This is the total in the question.911
Check. Check: 911 - 356 = 555.
Watch out. Look for words like more, altogether and in all. These mean add.
Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.
- Write the numbers in columns. Keep the ones under the ones and the tens under the tens.495 over 448
- Add the ones. The ones make 10 or more, so write the ones digit and carry 1 ten.5 + 8 = 13, write 3 and carry 1
- 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 + 4 + 1 carried = 14
- Add the hundreds. Add any carried hundred too.4 + 4 + 1 carried = 9
- Write the answer. Read the columns from left to right.943
Check. Check: 943 - 448 = 495.
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.
- Write the numbers in columns. Keep the ones under the ones and the tens under the tens.448 over 495
- Add the ones. The ones make 10 or more, so write the ones digit and carry 1 ten.8 + 5 = 13, write 3 and carry 1
- 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.4 + 9 + 1 carried = 14
- Add the hundreds. Add any carried hundred too.4 + 4 + 1 carried = 9
- Write the answer. Read the columns from left to right.943
Check. Check: 943 - 495 = 448.
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.
- Write the numbers in columns. Keep the ones under the ones and the tens under the tens.599 over 323
- 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
- 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 + 2 + 1 carried = 12
- Add the hundreds. Add any carried hundred too.5 + 3 + 1 carried = 9
- Write the answer. Read the columns from left to right.922
Check. Check: 922 - 323 = 599.
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.
- Write the numbers in columns. Keep the ones under the ones and the tens under the tens.323 over 599
- Add the ones. The ones make 10 or more, so write the ones digit and carry 1 ten.3 + 9 = 12, write 2 and carry 1
- 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.2 + 9 + 1 carried = 12
- Add the hundreds. Add any carried hundred too.3 + 5 + 1 carried = 9
- Write the answer. Read the columns from left to right.922
Check. Check: 922 - 599 = 323.
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.
- Write the numbers in columns. Keep the ones under the ones and the tens under the tens.327 over 124
- Add the ones. The ones make 10 or more, so write the ones digit and carry 1 ten.7 + 4 = 11, write 1 and carry 1
- Add the tens. Add the carried ten with the tens.2 + 2 + 1 carried = 5
- Add the hundreds. Add any carried hundred too.3 + 1 = 4
- Write the answer. Read the columns from left to right.451
Check. Check: 451 - 124 = 327.
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.
- Write the numbers in columns. Keep the ones under the ones and the tens under the tens.124 over 327
- Add the ones. The ones make 10 or more, so write the ones digit and carry 1 ten.4 + 7 = 11, write 1 and carry 1
- Add the tens. Add the carried ten with the tens.2 + 2 + 1 carried = 5
- Add the hundreds. Add any carried hundred too.1 + 3 = 4
- Write the answer. Read the columns from left to right.451
Check. Check: 451 - 327 = 124.
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.
- Write the numbers in columns. Keep the ones under the ones and the tens under the tens.860 over 59
- Add the ones. The ones make less than 10, so no ten is carried.0 + 9 = 9
- 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 + 5 = 11
- Add the hundreds. Add any carried hundred too.8 + 0 + 1 carried = 9
- Write the answer. Read the columns from left to right.919
Check. Check: 919 - 59 = 860.
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.
- Write the numbers in columns. Keep the ones under the ones and the tens under the tens.59 over 860
- Add the ones. The ones make less than 10, so no ten is carried.9 + 0 = 9
- 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.5 + 6 = 11
- Add the hundreds. Add any carried hundred too.0 + 8 + 1 carried = 9
- Write the answer. Read the columns from left to right.919
Check. Check: 919 - 860 = 59.
Watch out. When the tens make 10 or more, carry a hundred to the hundreds column.
Method. Round each number to the nearest hundred, then add the rounded numbers.
- Round 716 to the nearest hundred. Look at the tens and ones.716 is about 700
- Round 137 to the nearest hundred. Look at the tens and ones.137 is about 100
- Add the rounded numbers. This is the estimate.800
Check. The exact answer 853 should be close to 800.
Watch out. An estimate tells us roughly where the answer should be. It does not have to be exact.
Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.
- Write the numbers in columns. Keep the ones under the ones and the tens under the tens.716 over 137
- Add the ones. The ones make 10 or more, so write the ones digit and carry 1 ten.6 + 7 = 13, write 3 and carry 1
- Add the tens. Add the carried ten with the tens.1 + 3 + 1 carried = 5
- Add the hundreds. Add any carried hundred too.7 + 1 = 8
- Write the answer. Read the columns from left to right.853
Check. Check: 853 - 137 = 716.
Watch out. When the ones make 10 or more, carry a ten to the tens column. Do not forget it.
Method. Round each number to the nearest hundred, then add the rounded numbers.
- Round 717 to the nearest hundred. Look at the tens and ones.717 is about 700
- Round 83 to the nearest hundred. Look at the tens and ones.83 is about 100
- Add the rounded numbers. This is the estimate.800
Check. The exact answer 800 should be close to 800.
Watch out. An estimate tells us roughly where the answer should be. It does not have to be exact.
Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.
- Write the numbers in columns. Keep the ones under the ones and the tens under the tens.717 over 83
- Add the ones. The ones make 10 or more, so write the ones digit and carry 1 ten.7 + 3 = 10, write 0 and carry 1
- 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.1 + 8 + 1 carried = 10
- Add the hundreds. Add any carried hundred too.7 + 0 + 1 carried = 8
- Write the answer. Read the columns from left to right.800
Check. Check: 800 - 83 = 717.
Watch out. When the tens make 10 or more, carry a hundred to the hundreds column.
Method. Round each number to the nearest hundred, then add the rounded numbers.
- Round 213 to the nearest hundred. Look at the tens and ones.213 is about 200
- Round 639 to the nearest hundred. Look at the tens and ones.639 is about 600
- Add the rounded numbers. This is the estimate.800
Check. The exact answer 852 should be close to 800.
Watch out. An estimate tells us roughly where the answer should be. It does not have to be exact.
Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.
- Write the numbers in columns. Keep the ones under the ones and the tens under the tens.213 over 639
- Add the ones. The ones make 10 or more, so write the ones digit and carry 1 ten.3 + 9 = 12, write 2 and carry 1
- Add the tens. Add the carried ten with the tens.1 + 3 + 1 carried = 5
- Add the hundreds. Add any carried hundred too.2 + 6 = 8
- Write the answer. Read the columns from left to right.852
Check. Check: 852 - 639 = 213.
Watch out. When the ones make 10 or more, carry a ten to the tens column. Do not forget it.
Method. Round each number to the nearest hundred, then add the rounded numbers.
- Round 742 to the nearest hundred. Look at the tens and ones.742 is about 700
- Round 118 to the nearest hundred. Look at the tens and ones.118 is about 100
- Add the rounded numbers. This is the estimate.800
Check. The exact answer 860 should be close to 800.
Watch out. An estimate tells us roughly where the answer should be. It does not have to be exact.
Method. Add the ones, then the tens, then the hundreds. Carry any ten or hundred you make.
- Write the numbers in columns. Keep the ones under the ones and the tens under the tens.742 over 118
- Add the ones. The ones make 10 or more, so write the ones digit and carry 1 ten.2 + 8 = 10, write 0 and carry 1
- Add the tens. Add the carried ten with the tens.4 + 1 + 1 carried = 6
- Add the hundreds. Add any carried hundred too.7 + 1 = 8
- Write the answer. Read the columns from left to right.860
Check. Check: 860 - 118 = 742.
Watch out. When the ones make 10 or more, carry a ten to the tens column. Do not forget it.