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Write 1/3 as a decimal

Step by step, with the reason for every step · Fractions and decimals · Foundations

Step by step

The question

Question: write 1/3 as a decimal.

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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.

1 ÷ 3 = 0, 1 left

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.

10 ÷ 3 = 3, 1 left

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

= 0.333…
the 3 repeats

A repeating decimal never ends.

So we cannot multiply it back exactly.

The same leftover coming back is our check.

Answer
the 3 repeats

Your turn

Try this one yourself, then check:

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Show the answer
0.111…

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