Fractional Parts

If you spend one-fourth of a dollar, how much is left?
First divide the dollar into four equal pieces (the denominator -- bottom number -- tells how many equal pieces are in each whole thing). 100 ÷ 4 = 25. That's the amount used. What was the question? How much of the dollar is left?

You can set-up and solve this type of question as a proportion:

Use cross-products to solve: 3 times 100 = 4 times (the missing part)

3 times 100	=	4 times the amount left
300	=	4 times the amount left
300/4	=	4/4 times the amount left
75 (cents)	=	the amount left

Notice that the answer will be for whatever question you asked --the set-up can save you an extra step later (or save you from forgetting that there was a second step).

You fold one-third of sixty napkins. How many are left?

all 3/3 of the napkins minus 1/3 (already folded) shows that two-thirds of them left.

two-thirds of the 60 napkins are left to be folded. 2 times 60 divided by 3 equals 40 napkins left.

Jack's rent is two-fifths of his income. If he earns $1500, how much is his rent?

Jack earns $1500 and pays two-fifths of it for rent. 2 times 1500 divided by 5 equals &600 rent.

PRACTICE QUESTIONS:

1)	*Tom broke one-sixth of a dozen eggs. How many eggs are not* broken?**

2)	Kim ate one-fourth of sixty mints. How many mints are left?

3)	Pam painted three-fourths of the tiles. How many of the 80 tiles are painted?

4)	Dale sold one-eighth of the books. How many of the 40 books are left?

ANSWERS:

1) 10 eggs are UNBROKEN 2) 45 are left 3) 60 are painted 4) 35 are left

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