Rounding to the Nearest Ten

Rounding means changing a number to the closest ten. 23 rounds down to 20 because it is closer to 20. 27 rounds up to 30 because it is closer to 30. The number 25 rounds up to 30 by the usual rule.

Slide to any number. The lab shows the number on a number line, marks the two nearest tens, and tells you which one it rounds to. The ones digit decides up or down.

When Papa says the autorickshaw bill is around 50 rupees, he may have rounded 48 or 52. Shopkeepers often round to make change easier. Even reporting your study time uses rounding.

Look at the ones digit. If it is 0 to 4, round down. If it is 5 to 9, round up. So 31 to 34 become 30, but 35 to 39 become 40. This rule is the same for thousands and bigger.