We began our newest unit on extending decimal understanding by reviewing place value. I reminded my classes of whole number place value. We reiterated that we have a units, thousands, millions (etc.) period. That within each period is a 1, 10, 100 place. We discussed that when moving to the left in place value we are multiplying each place by 10 and when we move to the right, we divide by 10.
When we move into working with decimals, we are working with parts of a whole (just like fractions). Since we are moving to the right of the whole number, we are dividing by 10.
So, if we are in the "1" place, we divide by 10, which is the same as dividing a dollar by 10, this gives us dimes. A dime is 1/10 of a dollar or .1 of a dollar. This is our tenths place.
Using this same example, we discussed that dividing a dime by 10 would give us a penny. A penny is 1/100 of a dollar or .01 of a dollar. This is our hundredths place.
It becomes more difficult to divide a penny by ten, so we just wrote <penny over the thousandths place. I just wanted them to have a concrete idea to connect to decimals and using money was something they are comfortable with.
The focus of the lesson, however, was working with "10 times as much" and "1/10 of". We spent time with the textbook, using pages 11- 14, to work with patterns of multiplying and dividing by 10 with decimal numbers.
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