Decimal Operations Exploration Worksheet (Page 2 of 2) in pdf

Decimal Operations Exploration Worksheet Page 2

MATH 15

p. 2 of 2

e. How does multiplying and dividing decimals by whole numbers compare to ordinary

whole-number multiplication and division?

4. Use fractional equivalents to explore multiplication involving two decimals. Specifically,

perform each of the following calculations in two ways: first by changing the decimals to

fractional form and then multiplying, and second by using the standard multiplication

algorithm for decimals.

a. 0.1 x 0.3 =

b. 1.2 x 2.6 =

c. 0.8 x 1.45 =

d. 0.63 x 0.17 =

e. Why does “counting the number of decimal places” work in the standard algorithm for

multiplying decimals?

5. Use fractional equivalents to explore division involving two decimals. Specifically,

perform each of the following calculations in three ways: first, by changing the decimals to

fractional form and then dividing (notice what’s happening!); second, by writing the

division as a fraction and then multiplying by an appropriate fractional form of 1 to

eliminate all the decimal places; and third, by using the standard long division algorithm

for decimals.

a. 2.1

0.7 =

b. 0.48

1.2 =

c. 18.2

0.35 =

d. 0.1734

0.03 =

e. Why does “move the decimal points the same number of places in the divisor and the

dividend, and place the decimal point in the quotient above the moved point in the

dividend” work in the standard algorithm for dividing decimals?

Decimal Operations Exploration Worksheet Page 2