Wrap-Up and Assessment Hints Mental math exercises are helpful in strengthening students' skills with decimals.
Ask students to tell how many decimal places are the product of pairs of decimals, for example, 0.6 0.09 (4 places).
The difference is that the decimal point moves to the right when you multiply; it moves to the left when you divide.
In the examples above, notice that each quotient still contains the digits 4469—but as another 0 is added to the end of each power of ten in the divisor, the decimal point moves an additional place to the left in the quotient.
Recall that when you multiply a decimal by a power of ten (10, 100, 1,000, etc), the placement of the decimal point in the product will move to the right according to the number of zeros in the power of ten.
For instance, 4.12 Multiplication and division are inverse operations, so you can expect that if you divide a decimal by a power of ten, the decimal point in the quotient will also correspond to the number of zeros in the power of ten.To divide a decimal by a power of ten (10, 100, 1,000, etc.), count the number of zeros in the divisor.Then move the decimal point in the dividend that number of decimal places to the left; this will be your quotient.In cases like this, you can use powers of 10 to help create an easier problem to solve.In this case, you can multiply the The number that is being divided into the dividend in a division problem. divisor, 0.3, by 10 to move the decimal point 1 place to the right.Andy just sold his van that averaged 20 miles per gallon of gasoline.Learning to multiply and divide with decimals is an important skill.Identical wedges weighing 0.25 kg each are made from a big cheese weighing 2.5 kg. To solve this problem we have to think: With 2.5 kg of big cheese, how many wedges of 0.25 kg can we obtain?The whole cheese has been divided into equal parts, so in order to know how many wedges we can obtain, we should divide 2.5 kg by 0.25 kg: To solve this problem we should think: if Maria spent 3 times more than Vanessa than the money that Vanessa spent is 3 times less.You can think of this as moving the decimal point in the dividend the same number of places to the right as you move the decimal point in the divisor. Remember that when you divide, you do not count the total number of decimal places in the divisor and dividend.You change the divisor to a whole number, then move the decimal point in the dividend the same number of places and divide.