🍫 Fractions · Ages 7 to 11 · 1:07
Equivalent fractions: why 1/2 = 2/4 = 4/8
Two friends share a chocolate bar. Cut it into halves, quarters and eighths: the names change but the amount does not. Then the rule: multiply the top and the bottom by the same number.
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In this video
- 0:00 Share it fairly
- 0:38 The secret
- 0:54 Try one
Transcript
0:01 Here's a chocolate bar, and two friends who want to share it fairly.
0:05 Each friend gets one of two equal pieces. That's one half.
0:11 Now cut every piece in half again. Four pieces, and each friend has two of them.
0:19 Two quarters. But look, it's exactly the same amount of chocolate.
0:26 Cut once more. Eight pieces, and each friend has four. Four eighths.
0:32 One half, two quarters, four eighths. Different names, same amount.
0:39 Here's the secret. Each time we cut every piece in two, the top number and the bottom number both double.
0:47 Multiply the top and the bottom by the same number, and the fraction keeps its size.
0:54 So three quarters is the same as six eighths. Multiply by three, and it's nine twelfths.
1:01 Same amount, new name. That's an equivalent fraction.
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