Multiply numbers by 10, 100, and 1000 (and divide also) - 4th grade math

I show the easy shortcut for multiplying any number by 10, 100, or 1000. I also explain WHY IT WORKS... using a place value chart.

After that we solve a short word problem. Then we use this shortcut in DIVISION and divide numbers by 10, 100, or 1000. Lastly we solve another short word problem about age and years.