WorksheetsAbout this worksheet
Rounding gives a simpler number that is close to the real one. It is what we do when we say "about 500 people came". The rule: look at the digit just to the right of the place you are rounding to. If it is 5 or more, round up. If it is 4 or less, round down.
What this skill is
Rounding replaces a number with the nearest "round" number: the nearest ten, hundred or thousand. We use it to estimate, to check sums, and to speak about numbers without false exactness. Only one digit decides the result: the digit just to the right of the place being rounded to.
A worked example
Round 3,648 three ways.
- To the nearest 10: look at the ones digit, 8. It is 5 or more, so round up: 3,650.
- To the nearest 100: look at the tens digit, 4. It is less than 5, so round down: 3,600.
- To the nearest 1,000: look at the hundreds digit, 6. Round up: 4,000.
Each time, the digits to the right of the rounding place become zeros. "Rounding down" does not make the rounding digit smaller; it only leaves it as it is.
Tips for parents and teachers
- Draw a number line with the two nearest tens (or hundreds) and mark the number on it. The child can see which end is closer.
- A number exactly in the middle, such as 45 to the nearest ten, rounds up to 50. This is a rule people have agreed on.
- Use rounding to check sums: 398 + 204 should be near 400 + 200.
How to use this sheet at home and in class
- At home: draw a number line from 3,600 to 3,700, mark 3,648 on it and ask which end is nearer. Do this for the first few questions, then drop the drawing.
- In class: teach one rounding place per day. Mixed places belong to revision week.
- After the sheet, use rounding on yesterday's addition sheet: estimate each answer first and see how close it comes.
Mistakes to watch for
- Looking at the wrong digit, most often the last digit of the number, whatever the rounding place is.
- Rounding in stages: taking 3,448 to 3,450, then to 3,500. Rounded straight to the nearest hundred, 3,448 is 3,400. Always round from the original number.
- Trouble when rounding up crosses a place. 3,967 to the nearest ten is 3,970, but 3,997 to the nearest ten is 4,000, because 99 tens and one more ten make 400 tens.
What to try next
- Place value worksheets: if the child is unsure which digit is which.
- Decimals worksheets: estimating before adding.
- Percentage worksheets: for classes 5 to 7.