Tag: rounding

Resource of the Week: Rounding to the nearest million

One of the earliest posts that I made, back in 2007 was about rounding large numbers, up to millions. Many children are fascinated by large numbers and these two pages can help them both with reading and writing large numbers and rounding.

Thanks to mathsphere.co.uk for letting me use these resources, as they are taken from the ‘it’s All Figured Out’ CD.

Larger numbers can be rounded in just the same way as rounding hundreds or thousands; the key is to refer to the digit below the one you want to round.

Eg rounding to a million, look at the hundred thousand digit:

2 345 456 is rounded down to 2 000 000 (two million) to the nearest million because the hundred thousand digit is only 3.

2 987 654 is rounded up to 3 000 000 (three million) to the nearest million because the hundred thousand digit is 9.

There are plenty of good sources in geography, such as population figures, areas of countries etc

Rounding to the nearest million (pg 1)

Rounding to the nearest million (pg 2)

 

Year 5 maths worksheet: rounding measurements

Here we have a tricky little worksheet on rounding measurements, best suited to Year 5.

This is harder than most other rounding pages as the units change. For example, in the first question the units are shown in grams but the answer is required in kilograms, so the answer equires two steps:

1. round the number to the nearest 1000 (as there are 1000 grams in a kilogram)

2. change the unit from grams to kilograms.

Remember, when rounding to the nearest 1 000 it is the hundreds digit which is crucial: 5 or above round up, below 5 round down to the nearest 1000.

Rounding measurements

Year 6 revision: More rounding millions

Here we have another in our series of rounding larger numbers to the nearest million. This page looks in particular at the world’s oceans and the numbers involved have already been rounded to the nearest 1 000 sq km.

Children need to be confident when dealing with larger numbers, but this will only happen if they are secure in their knowledge of place value and how to read and write numbers. It may well be worth going back over this before attempting rounding.

Round to million  (oceans)

Year 6 revision: Rounding millions (1)

Many children in Year 6 have difficulty reading and writing large numbers, including millions. This page is all based on millions as it looks at the area in square kilometres of some of the largest countries in the world. The task is to round the numbers to the nearest million, and as it happens all of these need to be rounded down.

It is well worth ‘talking through’ this page to make sure that the numbers are read correctly.

Round to million 1 (countries)

Year 5 maths worksheet: Rounding to the nearest thousand (2)

This is a follow up page to our earlier worksheet on rounding for year 5 children.When rounding to the nearest thousand the key digit is the hundreds digit. If it is 5 or more round up to the next whole thousand. If it is less than 5 then take away the hundreds tens and units and leave the number ’rounded down’.

With practice children should be able to round numbers quickly and also begin to see what is a sensible rounding. Should it be to the nearest hundred, thousand or ten thousand?

Round to the_nearest_1000_(2)

Year 5 maths worksheet: Rounding to 1000

Many people criticise the fact that children use calculators and, indeed, they have huge potential for giving incorrect answers: numbers left in the memory and mishit keys are just two ways of ensuring wrong answers. That is why it is so important that a mental calculation, no matter how brief, always goes on at the same time as the calculator is used, to ensure that the answer is ‘sensible’.

For example, a child might want to know quickly what 3 876 x 3 is. By all means use the calculator, but at the same time, he should be rounding 3 876 to 4 000 and multiplying 4 000 by 3 to make 12 000. This should take only a second or so to do in his head. He then knows that the answer will be just less than 12 000.

3 876 x 3 is actually 11 628

This is why the ability to round quickly and sensibly is so important. Hence this worksheet, found in our Year 5 Counting and Number section.

Round to the nearest_1000

Year 6 maths worksheet: Rounding to 10 000 (2)

Here we have a re-inforcement page for the recently published page on how to round numbers to the nearest 10 000.

Useful as a homework sheet or consolidation for those who are still unsure about how to do this. Children do not come across larger numbers very often and it can also be used as practice at reading larger numbers out loud.

Practice:_round to the nearest 10 000

Year 6 maths worksheet: Rounding to 10 000

Rounding larger numbers can be tricky to understand as you get different results depending on what you round to.

For example 12 345 rounded to the nearest 10 is 12 350, to the nearest 100 is 12 300, to the nearest 1 000 is 12 000 and to the nearest 10 000 is 10 000. What you round to will depend on the circumstances and how accurate your rounding needs to be.

These pages look at how to round to the nearest 10 000. In this case the two crucial digits to look at are the ten thousand and the thousands digits.

How to round nearest 10 000

Year 6 Maths Worksheet: Rounding decimals

rounding-decimals-y6-p1When rounding decimals to the nearest whole one the only digits that are crucial are the tenths – it does not matter what the hundredths or thousandths are.

When rounding a number such as 3.47 to the nearest whole number the key digit to look at is the tenths digit. If it is 5 or more, round up. Less than 5, round down.

So 3.44 rounded to the nearest whole one is 3.

3.47 rounded to the nearest whole one is 4.

Year 6 Rounding decimals (pg 1)

Maths worksheet: Rounding to the nearest 10

If the units are 5 or more, round up to the next whole ten.

round-to-nearest-10Rounding to the nearest ten is a simple process but can cause confusion. The key digit to look at is the units digit. The rule is:

If the units are 5 or more, round up to the next whole ten.

If the units are less than 5, round down to the next whole ten below.

Of course, if the units are zero then there is no need to round. (Some children think they have to go down ten more!)

So, 56 to the nearest whole ten is 60

55 to the nearest whole ten is 60

53 to the nearest 10 is 50

Rounding to the nearest 10