1. Multiplying & Dividing by 10 & 100

2. Multiply by 10 The easy way to x10 is to add a zero! So 19 x 10 = 190 46 x 10 = 460 12 x 10 = 120

3. Try these: 29 x 10 30 x 10 19 x 10 54 x 10 98 x 10 28 x 10 13 x 10 290 300 190 540 980 280 130 65 x 10 67 x 10 89 x 10 78 x 10 81 x 10 11 x 10 650 670 890 780 810 110

4. But that only works if there is no decimal point What will we do if there is a decimal point? 12.4 x 10 = ? We’ll move the figures one place to the right. Moving to the right makes the number smaller. Let’s try some.

5. Remember: move 1 place to the right. H T U. t h 5. 4 5. 4 5 4 5 4. Notice that the decimal point is in the same place – the decimal point never moves!

6. Always remember place value M HTh TTh Th H T U. t h th Millions Hundreds of Thousands Hundreds of Thousands Tens of Thousands Tens of Thousands Thousands Thousands Hundreds Hundreds Tens Tens Units Units decimal point decimal point tenths tenths hundredths hundredths thousandths thousandths Decimal point is always between the Units and the tenths.

7. Try these: 13.5 x 10 65.3 x 10 78.2 x 10 65.2 x 10 15.9 x 10 49.2 x 10 6.2 x 10 1.9 x 10 135 653 782 652 159 492 62 19