Step-by-step Maths Level 3: Estimating on a number line from 0 to 1000
Part of the Step-by-step Maths Level 3 comparing and ordering to 1000 chapter. Chapter overview · whole chapter on one page
Estimating on a number line from 0 to 1000
On a number line from 0 to 1000, the hundreds are marked. A number between two hundreds is about halfway if it ends in 50.
To estimate, round to the nearest hundred. Look at the tens and ones.
Key ideas
- Count the hundreds marked on the line.
- Round to the nearest hundred when you estimate.
- If the tens and ones are 50 or more, the number is nearer to the next hundred.
Method. Find the hundreds either side. The nearer one is the answer.
- Find the hundreds either side of 738. These are the two hundreds the number is between.700 and 800
- Find which hundred is nearer. 738 - 700 = 38, and 800 - 738 = 62.38 is less than 62
- Write the nearest hundred. This is the answer.700
Check. 700 is 38 away from 738, and the other hundred is further away.
Watch out. Look at the tens and ones. If they are 50 or more, round up. If less than 50, round down.
Method. Find the hundreds either side. The nearer one is the answer.
- Find the hundreds either side of 412. These are the two hundreds the number is between.400 and 500
- Find which hundred is nearer. 412 - 400 = 12, and 500 - 412 = 88.12 is less than 88
- Write the nearest hundred. This is the answer.400
Check. 400 is 12 away from 412, and the other hundred is further away.
Watch out. Look at the tens and ones. If they are 50 or more, round up. If less than 50, round down.
Method. Find the distance from the number to each hundred. The shorter distance is the nearer one.
- Find the two hundreds. 683 is between 600 and 700.600 < 683 < 700
- Compare the distances. 683 - 600 = 83, 700 - 683 = 17.83 and 17
- Write the nearer hundred. The smaller distance is the nearer hundred.700
Check. 700 is nearer to 683 than the other hundred.
Watch out. The number is nearer to 600 than to 700 when it is less than 650.
Watch out
Watch out. 738 is nearer to 700 than to 800, because it is only 38 more than 700. Do not round to the wrong hundred.
Exam tip
Grown-up tip. Draw a number line on paper and mark the hundreds. Ask: “Is the number closer to the left or the right?”
Exercise 3D Practice: estimating on a number line
Non-calculatorMethod. Find the distance from the number to each hundred. The shorter distance is the nearer one.
- Find the two hundreds. 903 is between 900 and 1000.900 < 903 < 1000
- Compare the distances. 903 - 900 = 3, 1000 - 903 = 97.3 and 97
- Write the nearer hundred. The smaller distance is the nearer hundred.900
Check. 900 is nearer to 903 than the other hundred.
Watch out. The number is nearer to 600 than to 700 when it is less than 650.
Method. Find the hundreds either side. The nearer one is the answer.
- Find the hundreds either side of 708. These are the two hundreds the number is between.700 and 800
- Find which hundred is nearer. 708 - 700 = 8, and 800 - 708 = 92.8 is less than 92
- Write the nearest hundred. This is the answer.700
Check. 700 is 8 away from 708, and the other hundred is further away.
Watch out. Look at the tens and ones. If they are 50 or more, round up. If less than 50, round down.
Method. Find the hundreds either side. The nearer one is the answer.
- Find the hundreds either side of 822. These are the two hundreds the number is between.800 and 900
- Find which hundred is nearer. 822 - 800 = 22, and 900 - 822 = 78.22 is less than 78
- Write the nearest hundred. This is the answer.800
Check. 800 is 22 away from 822, and the other hundred is further away.
Watch out. Look at the tens and ones. If they are 50 or more, round up. If less than 50, round down.
Method. Find the hundreds either side. The nearer one is the answer.
- Find the hundreds either side of 966. These are the two hundreds the number is between.900 and 1000
- Find which hundred is nearer. 966 - 900 = 66, and 1000 - 966 = 34.34 is less than 66
- Write the nearest hundred. This is the answer.1000
Check. 1000 is 34 away from 966, and the other hundred is further away.
Watch out. Look at the tens and ones. If they are 50 or more, round up. If less than 50, round down.
Method. Find the distance from the number to each hundred. The shorter distance is the nearer one.
- Find the two hundreds. 976 is between 900 and 1000.900 < 976 < 1000
- Compare the distances. 976 - 900 = 76, 1000 - 976 = 24.76 and 24
- Write the nearer hundred. The smaller distance is the nearer hundred.1000
Check. 1000 is nearer to 976 than the other hundred.
Watch out. The number is nearer to 600 than to 700 when it is less than 650.
Method. Find the hundreds either side. The nearer one is the answer.
- Find the hundreds either side of 848. These are the two hundreds the number is between.800 and 900
- Find which hundred is nearer. 848 - 800 = 48, and 900 - 848 = 52.48 is less than 52
- Write the nearest hundred. This is the answer.800
Check. 800 is 48 away from 848, and the other hundred is further away.
Watch out. Look at the tens and ones. If they are 50 or more, round up. If less than 50, round down.
Method. Find the distance from the number to each hundred. The shorter distance is the nearer one.
- Find the two hundreds. 826 is between 800 and 900.800 < 826 < 900
- Compare the distances. 826 - 800 = 26, 900 - 826 = 74.26 and 74
- Write the nearer hundred. The smaller distance is the nearer hundred.800
Check. 800 is nearer to 826 than the other hundred.
Watch out. The number is nearer to 600 than to 700 when it is less than 650.
Method. Find the hundreds either side. The nearer one is the answer.
- Find the hundreds either side of 357. These are the two hundreds the number is between.300 and 400
- Find which hundred is nearer. 357 - 300 = 57, and 400 - 357 = 43.43 is less than 57
- Write the nearest hundred. This is the answer.400
Check. 400 is 43 away from 357, and the other hundred is further away.
Watch out. Look at the tens and ones. If they are 50 or more, round up. If less than 50, round down.
Method. Find the hundreds either side. The nearer one is the answer.
- Find the hundreds either side of 849. These are the two hundreds the number is between.800 and 900
- Find which hundred is nearer. 849 - 800 = 49, and 900 - 849 = 51.49 is less than 51
- Write the nearest hundred. This is the answer.800
Check. 800 is 49 away from 849, and the other hundred is further away.
Watch out. Look at the tens and ones. If they are 50 or more, round up. If less than 50, round down.
Method. Find the distance from the number to each hundred. The shorter distance is the nearer one.
- Find the two hundreds. 982 is between 900 and 1000.900 < 982 < 1000
- Compare the distances. 982 - 900 = 82, 1000 - 982 = 18.82 and 18
- Write the nearer hundred. The smaller distance is the nearer hundred.1000
Check. 1000 is nearer to 982 than the other hundred.
Watch out. The number is nearer to 600 than to 700 when it is less than 650.
Method. Find the distance from the number to each hundred. The shorter distance is the nearer one.
- Find the two hundreds. 141 is between 100 and 200.100 < 141 < 200
- Compare the distances. 141 - 100 = 41, 200 - 141 = 59.41 and 59
- Write the nearer hundred. The smaller distance is the nearer hundred.100
Check. 100 is nearer to 141 than the other hundred.
Watch out. The number is nearer to 600 than to 700 when it is less than 650.
Method. Find the hundreds either side. The nearer one is the answer.
- Find the hundreds either side of 443. These are the two hundreds the number is between.400 and 500
- Find which hundred is nearer. 443 - 400 = 43, and 500 - 443 = 57.43 is less than 57
- Write the nearest hundred. This is the answer.400
Check. 400 is 43 away from 443, and the other hundred is further away.
Watch out. Look at the tens and ones. If they are 50 or more, round up. If less than 50, round down.
Method. Find the hundreds either side. The nearer one is the answer.
- Find the hundreds either side of 433. These are the two hundreds the number is between.400 and 500
- Find which hundred is nearer. 433 - 400 = 33, and 500 - 433 = 67.33 is less than 67
- Write the nearest hundred. This is the answer.400
Check. 400 is 33 away from 433, and the other hundred is further away.
Watch out. Look at the tens and ones. If they are 50 or more, round up. If less than 50, round down.
Method. Find the distance from the number to each hundred. The shorter distance is the nearer one.
- Find the two hundreds. 744 is between 700 and 800.700 < 744 < 800
- Compare the distances. 744 - 700 = 44, 800 - 744 = 56.44 and 56
- Write the nearer hundred. The smaller distance is the nearer hundred.700
Check. 700 is nearer to 744 than the other hundred.
Watch out. The number is nearer to 600 than to 700 when it is less than 650.
Method. Find the hundreds either side. The nearer one is the answer.
- Find the hundreds either side of 232. These are the two hundreds the number is between.200 and 300
- Find which hundred is nearer. 232 - 200 = 32, and 300 - 232 = 68.32 is less than 68
- Write the nearest hundred. This is the answer.200
Check. 200 is 32 away from 232, and the other hundred is further away.
Watch out. Look at the tens and ones. If they are 50 or more, round up. If less than 50, round down.
Method. Find the hundreds either side. The nearer one is the answer.
- Find the hundreds either side of 811. These are the two hundreds the number is between.800 and 900
- Find which hundred is nearer. 811 - 800 = 11, and 900 - 811 = 89.11 is less than 89
- Write the nearest hundred. This is the answer.800
Check. 800 is 11 away from 811, and the other hundred is further away.
Watch out. Look at the tens and ones. If they are 50 or more, round up. If less than 50, round down.