Maths: Rounding

In a rounding question, you round a number to the nearest ten, hundred or thousand. Or it's turned round: you're given the rounded number, and you find which number rounds to it. There are five answers to choose from.

There's no calculator, and only one of the five answers is right.

In GL's papers rounding comes turned round, and its wrong answers round to the next ten, the ten before, or the wrong place. Rounding also hides inside longer stories, where a remainder has to round up. The video above and the worked example below work through the same question, with the options in the same order. Then both work a second, short question, the usual way round.

The method

Four steps: find the column, find the round numbers either side, look at the next figure, fill the rest with zeros.

Worked example

Which of these numbers rounds to 950 when it is rounded to the nearest ten?

A. 9,497 B. 941 C. 959 D. 952 E. 961

1. Find the column. The question says the nearest ten, so the tens column is the one that matters. 950 is a round ten: its tens figure is a 5, with a zero after it.
2. Find the round numbers either side. Each number sits between two round tens. 961 sits between 960 and 970. Neither of those is 950, so E is out. 9,497 sits between 9,490 and 9,500. That looks like 950, but it's ten times bigger, so A is out.
3. Look at the next figure. 5 or more rounds up, and 4 or less rounds down. 941 ends in a 1, so it rounds down to 940. B is out. 959 ends in a 9, so it rounds up to 960. Cutting the 9 off isn't rounding, so C is out. 952 ends in a 2, so it rounds down.
4. Fill the rest with zeros. Every place after the tens becomes a zero, so 952 becomes 950. So the answer is D.

Answer: D — 952 (952 is between 950 and 960, and a 2 rounds down)

A second worked example

Now one the usual way round.

What is 7,398 rounded to the nearest ten?

A. 7,300 B. 7,390 C. 7,400 D. 7,408 E. 7,490

1. Find the column. The tens figure is a 9.
2. Find the round numbers either side. 7,390 and 7,400. A is neither of those, so A is out. Nor is E, so E is out too.
3. Look at the next figure. An 8, so round up, to 7,400. B rounded down, so B is out.
4. Fill the rest with zeros. One more ten makes ten tens, which is a new hundred. So the tens and the ones are both zeros. D kept its 8, so D is out. The answer is C.

Answer: C — 7,400 (7,398 rounds up; ten tens make a hundred)

Things to watch out for

1. Round to the place asked. Nearest hundred: not ten, not thousand. What is 6,673 rounded to the nearest hundred? It sits between 6,600 and 6,700, and the next figure is a 7, so it rounds up: 6,700. A is the nearest ten, and B is the nearest thousand.
2. A remainder can round up. Think about what the story needs. 29 children are going to a match, 3 to a car. 9 cars take 27 children, so 2 are left over. They still need a car, so they need 10 cars. 9 would leave two children behind.
3. Decimals round the same way. Nearest centimetre? Look after the point. Logan's pencil is 25.6 cm long. How long is it to the nearest centimetre? The column is the ones, and the next figure is the 6 after the point, so round up: 26 cm. B just drops the .6. That's cutting, not rounding.

Related

• The complete 11+ question-type guide
• Maths: Place Value and Ordering — the column a figure sits in gives its value
• Maths: Written Calculation — round first to estimate, then cross off by size
• Maths: Word Problems — check the answer fits the story

All example questions come from the Brainblox question bank — practise this question type inside 25+ learning games, timed mock exams and focused practice. Brainblox is an independent app: not affiliated with, endorsed by or licensed by any exam board, school or assessment publisher, and it contains no past papers.