Solve the following problems. Use a diagram to show the facts of the problem. See Example....

Solve the following problems. Use a diagram to show the facts of the problem. See Example.

DOOR MATS There are 7 square yards of carpeting left on a roll. How many 4-square-foot door mats can be made from the roll? (Hint: There are 9 square feet in one square yard.)

Example

Bottled Water How many 6-ounce servings are there in a 5-gallon bottle of water? (Hint: There are 128 fluid ounces in 1 gallon.)

Analyze The diagram on the next page is helpful in understanding the problem.

· Since each of the 5 gallons of water is 128 ounces, the total number of ounces is the sum of five 128’s. This repeated addition can be calculated using multiplication.

· Since equal-sized servings of water come from the bottle, this suggests division.

· Therefore, to solve this problem, we need to perform two operations: multiplication and division.

Form (Step 1) There are 640 ounces of water in the 5-gallon bottle. To find the number of ounces of water in the 5-gallon bottle, we multiply:

Form (Step 2) Now we use the answer from Step 1 to find the number of 6-ounce servings.

Calculate Use long division to find 640 ÷ 6.

State In a 5-gallon bottle of water, there are 106 6-ounce servings, with 4 ounces of water left over.

Check To check the multiplication, use estimation. To check the division, use the relationship: (Quotient · divisor) + remainder = dividend.