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Multiplying and dividing by 10 and 100 is easy…. …when you know how!. Make sure you keep an eye on the place – value markers…they’re REALLY important. Th H T U . t h 3 2 . 1 0
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Multiplying and dividing by 10 and 100 is easy….. …when you know how!
Make sure you keep an eye on the place – value markers…they’re REALLY important. Th H T U . t h 3 2 . 1 0 Multiply it by 10, so every digit becomes 10 times BIGGER. EVERY digit moves one place to the LEFT. Th H T U . t h 3 2 . 1 0 3 2 1 . 0
Lets look at that again… • We’ll multiply 56.03 by 10. • Remember what happens to EACH digit. • Th H T U . t h • 5 6 . 0 3 X10 • 5 6 0 . 3 • Check that the order of the digits is the same as when you started.
So what happens when you multiply by 100…let’s see • TH H T U . t h • 4 6 . 0 2 X 100 4 6 0 2 . • See! Each digit moves across two places to the left…and of course • 100 has 2 zeros, so that’s a good reminder. The number becomes 100 times bigger
Now if you make numbers bigger by moving them to the left…what do you think happens when you divide numbers by 10? • Yes… you move each digit one place to the right, to make it 10 times smaller! • Like this… • TH H T U . t h • 3 5 0 . 0 • 3 5 . 0 0 • REALLY IMPORTANT!!!!!!!!!! See how the decimal point stays inn the same place.
So now you can guess what happens when you divide by 100. • That’s right, every digit moves two places to the right to make the number 100 times smaller. • Lets divide 12.6 into 100 bits…wow how tiny would each bit be? • TH H T U . t h th t.th • 1 2 . 6 0 divided by 100 • 0 . 1 2 6 0 • So 0.1260 is 100 times smaller than 12.6
