Here is a number that turns up on a receipt all the time: 4.7.

If someone asked you to round it to the nearest whole number, would you say 4 or 5? Hands up when you have decided, and be ready to say how you know.

The number line shows a number caught between two whole numbers or two decimals. Watch where the marker sits compared to the halfway point. Which end is it closer to?

Now we round some together on one number line, zooming to each number in turn. We start with 3.2 to the nearest whole (which whole is it closer to?), then 0.68 to the nearest tenth (the deciding digit is 8, so watch what happens), and finally 0.95 to the nearest tenth.

Today we work through these on the board, one at a time: round 0.628 to the nearest tenth, then 9.5 to the nearest whole, then 1.275 to the nearest hundredth, and finally 9.96 to the nearest tenth. Say the deciding digit aloud each time before we check.