Number Lines 1 - 10
Number lines can be used to help when rounding. Numbers round down when they are closer to zero and up when they are closer to the next number. Place value and the counting system is understood well before learning how to round. The graph below shows a set of number lines 1 - 10 (one to ten).
Number Lines 1 - 20
The numbers which are less than zero are called negative numbers. The image below shows a set of number lines 1 - 20 (one to twenty).
Rounding Chart Nearest Ten
When rounding to the nearest ten we might use a rounding chart. In the rounding chart below the numbers shaded in grey round down. For example, 23 when rounded to the nearest ten rounds down to 20. 74 when rounded to the nearest ten rounds down to 70. The numbers which end in 5, or higher than 5, round up. For example, 19 rounded to the nearest ten is 20. 48 rounded to the nearest ten is 50.
The examples below show the answer when 4.63, 5.75 and 1.98 are rounded to 1 decimal place.
Rounding Chart Nearest Whole
The graphic below shows a rounding chart to the nearest whole. Numbers which end with .5 (or point five), round up. Whereas numbers which end with .4, .3, .2 or .1 round down. For example 0.2 rounded to the nearest whole number is zero. 8.4 when rounded to the nearest whole number is 8. 5.7 when rounded to the nearest whole number is 6, and so on.
How To Round Numbers
The example below demonstrates how to round to the nearest significant figure. When rounding to significant figures we remember that if the number starts with zero then it is not significant. In the example below the first numbers are all significant figures. For harder examples try the Significant Figures Worksheets Page.