Step-by-step Maths Level 5: Rounding to the nearest 10, 100, 1000, 10000 and 100,000
Part of the Step-by-step Maths Level 5 place value to a million and decimals to tenths chapter. Chapter overview · whole chapter on one page
Rounding to the nearest 10, 100, 1000, 10000 and 100,000
To round, look at the digit just to the right of the column you are rounding to. If it is 5 or more, round up. If it is 4 or less, round down.
Then replace all the digits to the right of that column with zeros.
Key ideas
- Look one column to the right of the rounding column.
- 5 or more: round up. 4 or less: round down.
- Replace the digits after the rounding column with zeros.
Method. Look at the digit to the right of the thousands column, then decide.
- Look at the hundreds digit. This digit decides whether to round up or down.The hundreds digit is 8
- Decide: round up or down. 5 or more: round up. 4 or less: round down.8 is 5 or more, so round up
- Write the rounded number. Replace the digits after the thousands column with zeros.473,000
Check. Check: 473,000 is a multiple of 1,000 and is the closest one to 472,893.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Look at the digit to the right of the hundred thousands column, then decide.
- Look at the ten thousands digit. This digit decides whether to round up or down.The ten thousands digit is 7
- Decide: round up or down. 5 or more: round up. 4 or less: round down.7 is 5 or more, so round up
- Write the rounded number. Replace the digits after the hundred thousands column with zeros.500,000
Check. Check: 500,000 is a multiple of 100,000 and is the closest one to 472,893.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Look at the digit to the right of the ten thousands column, then decide.
- Look at the thousands digit. This digit decides whether to round up or down.The thousands digit is 6
- Decide: round up or down. 5 or more: round up. 4 or less: round down.6 is 5 or more, so round up
- Write the rounded number. Replace the digits after the ten thousands column with zeros.300,000
Check. Check: 300,000 is a multiple of 10,000 and is the closest one to 296,458.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Watch out
Watch out. Round up only when the next digit is 5 or more. 472,893 to the nearest 1,000 is 473,000, not 472,000.
Exam tip
Grown-up tip. Ask the child to point to the digit that decides, and say “up” or “down” before writing the answer.
Exercise 1C Practice: rounding
Non-calculatorMethod. Look at the digit to the right of the hundreds column, then decide.
- Look at the tens digit. This digit decides whether to round up or down.The tens digit is 5
- Decide: round up or down. 5 or more: round up. 4 or less: round down.5 is 5 or more, so round up
- Write the rounded number. Replace the digits after the hundreds column with zeros.394,700
Check. Check: 394,700 is a multiple of 100 and is the closest one to 394,653.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Look at the digit to the right of the tens column, then decide.
- Look at the ones digit. This digit decides whether to round up or down.The ones digit is 9
- Decide: round up or down. 5 or more: round up. 4 or less: round down.9 is 5 or more, so round up
- Write the rounded number. Replace the digits after the tens column with zeros.365,660
Check. Check: 365,660 is a multiple of 10 and is the closest one to 365,659.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Look at the digit to the right of the tens column, then decide.
- Look at the ones digit. This digit decides whether to round up or down.The ones digit is 5
- Decide: round up or down. 5 or more: round up. 4 or less: round down.5 is 5 or more, so round up
- Write the rounded number. Replace the digits after the tens column with zeros.358,140
Check. Check: 358,140 is a multiple of 10 and is the closest one to 358,135.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Look at the digit to the right of the tens column, then decide.
- Look at the ones digit. This digit decides whether to round up or down.The ones digit is 5
- Decide: round up or down. 5 or more: round up. 4 or less: round down.5 is 5 or more, so round up
- Write the rounded number. Replace the digits after the tens column with zeros.973,430
Check. Check: 973,430 is a multiple of 10 and is the closest one to 973,425.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Look at the digit to the right of the hundreds column, then decide.
- Look at the tens digit. This digit decides whether to round up or down.The tens digit is 8
- Decide: round up or down. 5 or more: round up. 4 or less: round down.8 is 5 or more, so round up
- Write the rounded number. Replace the digits after the hundreds column with zeros.307,700
Check. Check: 307,700 is a multiple of 100 and is the closest one to 307,682.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Look at the digit to the right of the tens column, then decide.
- Look at the ones digit. This digit decides whether to round up or down.The ones digit is 3
- Decide: round up or down. 5 or more: round up. 4 or less: round down.3 is 4 or less, so round down
- Write the rounded number. Replace the digits after the tens column with zeros.346,080
Check. Check: 346,080 is a multiple of 10 and is the closest one to 346,083.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Look at the digit to the right of the tens column, then decide.
- Look at the ones digit. This digit decides whether to round up or down.The ones digit is 9
- Decide: round up or down. 5 or more: round up. 4 or less: round down.9 is 5 or more, so round up
- Write the rounded number. Replace the digits after the tens column with zeros.357,570
Check. Check: 357,570 is a multiple of 10 and is the closest one to 357,569.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Look at the digit to the right of the tens column, then decide.
- Look at the ones digit. This digit decides whether to round up or down.The ones digit is 1
- Decide: round up or down. 5 or more: round up. 4 or less: round down.1 is 4 or less, so round down
- Write the rounded number. Replace the digits after the tens column with zeros.374,520
Check. Check: 374,520 is a multiple of 10 and is the closest one to 374,521.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Look at the digit to the right of the thousands column, then decide.
- Look at the hundreds digit. This digit decides whether to round up or down.The hundreds digit is 6
- Decide: round up or down. 5 or more: round up. 4 or less: round down.6 is 5 or more, so round up
- Write the rounded number. Replace the digits after the thousands column with zeros.790,000
Check. Check: 790,000 is a multiple of 1,000 and is the closest one to 789,603.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Look at the digit to the right of the hundreds column, then decide.
- Look at the tens digit. This digit decides whether to round up or down.The tens digit is 0
- Decide: round up or down. 5 or more: round up. 4 or less: round down.0 is 4 or less, so round down
- Write the rounded number. Replace the digits after the hundreds column with zeros.435,800
Check. Check: 435,800 is a multiple of 100 and is the closest one to 435,802.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Look at the digit to the right of the thousands column, then decide.
- Look at the hundreds digit. This digit decides whether to round up or down.The hundreds digit is 9
- Decide: round up or down. 5 or more: round up. 4 or less: round down.9 is 5 or more, so round up
- Write the rounded number. Replace the digits after the thousands column with zeros.829,000
Check. Check: 829,000 is a multiple of 1,000 and is the closest one to 828,908.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Look at the digit to the right of the hundreds column, then decide.
- Look at the tens digit. This digit decides whether to round up or down.The tens digit is 8
- Decide: round up or down. 5 or more: round up. 4 or less: round down.8 is 5 or more, so round up
- Write the rounded number. Replace the digits after the hundreds column with zeros.492,000
Check. Check: 492,000 is a multiple of 100 and is the closest one to 491,985.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Look at the digit to the right of the ten thousands column, then decide.
- Look at the thousands digit. This digit decides whether to round up or down.The thousands digit is 2
- Decide: round up or down. 5 or more: round up. 4 or less: round down.2 is 4 or less, so round down
- Write the rounded number. Replace the digits after the ten thousands column with zeros.820,000
Check. Check: 820,000 is a multiple of 10,000 and is the closest one to 822,128.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Look at the digit to the right of the hundred thousands column, then decide.
- Look at the ten thousands digit. This digit decides whether to round up or down.The ten thousands digit is 6
- Decide: round up or down. 5 or more: round up. 4 or less: round down.6 is 5 or more, so round up
- Write the rounded number. Replace the digits after the hundred thousands column with zeros.200,000
Check. Check: 200,000 is a multiple of 100,000 and is the closest one to 169,143.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Look at the digit to the right of the hundreds column, then decide.
- Look at the tens digit. This digit decides whether to round up or down.The tens digit is 2
- Decide: round up or down. 5 or more: round up. 4 or less: round down.2 is 4 or less, so round down
- Write the rounded number. Replace the digits after the hundreds column with zeros.285,000
Check. Check: 285,000 is a multiple of 100 and is the closest one to 285,029.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Look at the digit to the right of the ten thousands column, then decide.
- Look at the thousands digit. This digit decides whether to round up or down.The thousands digit is 0
- Decide: round up or down. 5 or more: round up. 4 or less: round down.0 is 4 or less, so round down
- Write the rounded number. Replace the digits after the ten thousands column with zeros.320,000
Check. Check: 320,000 is a multiple of 10,000 and is the closest one to 320,850.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.