Fractions, decimals, percentages

Hello, and welcome to Myriora Maths! One half, nought point five, and fifty per cent. That's three different ways to write the same amount! Let's learn to swap between them.

Look at this bar. Half of it is coloured. As a fraction, that's one half. As a decimal, it's nought point five. As a percentage, it's fifty per cent. All three show the same amount!

Decimals and percentages are easy to swap. Per cent means hundredths. Nought point three seven is thirty-seven hundredths, so it's thirty-seven per cent. Just times by a hundred, and the digits move two places.

To turn a fraction into a percentage, make the bottom a hundred. For three fifths, times the top and the bottom by twenty. That's sixty hundredths: sixty per cent!

Some are worth knowing by heart. A quarter is nought point two five, or twenty-five per cent. Three quarters is nought point seven five, or seventy-five per cent. A tenth is nought point one, or ten per cent. And a fifth is nought point two, or twenty per cent.

Let's try one together. What is nought point nine as a percentage? Say it out loud!

Nought point nine is ninety hundredths. So it's ninety per cent!

Here's a question that catches lots of people. What is nought point nought five as a percentage? Some people say fifty per cent. But nought point nought five is five hundredths. So it's five per cent!

Your turn! Which of these is the biggest: two fifths, nought point three five, or thirty-eight per cent? Pick the right card. You've got twenty seconds, or pause the video. Go!

Time's up! Turn them all into percentages. Two fifths is forty per cent. Nought point three five is thirty-five per cent. So two fifths is the biggest!

Quick review. Fractions, decimals and percentages can show the same amount. To turn a decimal into a percentage, times by a hundred. To turn a fraction into a percentage, make the bottom a hundred. To compare them, turn them all into percentages. See you next time!