Write 3/10 as a decimal Easy

The question

Question: write 3/10 as a decimal.

1 Write the decimal

10 has 1 zero.

So the decimal has 1 digit after the point.

3 tenths is 0.3.

2 Check

Let's check: the decimal times the bottom should give the top.

0.3 times 10.

Forget the points: 3 times 10 is 30.

The numbers have 1 digit after the point.

So the answer has 1 too: 3.0, which is 3.

We get 3, the top.

So the answer is right!

Let's look back.

First: write the decimal.

Last: check.

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Write 3/4 as a decimal Medium

The question

Question: write 3/4 as a decimal.

1 Make the bottom 10, 100 or 1000

A decimal is tenths, hundredths, thousandths.

So we want a bottom of 10, 100 or 1000.

4 times 25 is 100.

We multiply the top and the bottom by 25.

25/25 is 1, so the value stays the same.

3 times 25 is 75.

So we get 75/100.

2 Write the decimal

100 has 2 zeros.

So the decimal has 2 digits after the point.

75 hundredths is 0.75.

3 Check

Let's check: the decimal times the bottom should give the top.

0.75 times 4.

Forget the points: 75 times 4 is 300.

The numbers have 2 digits after the point.

So the answer has 2 too: 3.00, which is 3.

We get 3, the top.

So the answer is right!

Let's look back.

First: make the bottom 10, 100 or 1000.

Then: write the decimal.

Last: check.

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Write 1/3 as a decimal Harder

The question

Question: write 1/3 as a decimal.

1 Divide

The bottom 3 does not go into 10, 100 or 1000.

So we divide: 1 ÷ 3, one digit at a time.

1 ÷ 3 is 0, with 1 left.

So we write 0 and the point.

We put a 0 next to the 1 left: 10.

10 ÷ 3 is 3, with 1 left.

1 left again: the same as before.

So the digits repeat for ever.

So 1/3 is 0.333…, and the 3 repeats for ever.

A repeating decimal never ends.

So we cannot multiply it back exactly.

The same leftover coming back is our check.

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