# i hate math

Four fifths of a dollar is how many cents?

First, divide the dollar into five equal piles of pennies (fifth = five).

Second, count how many pennies there are in four of the piles.

. . .

### Comments for i hate math

 Dec 07, 2010 Using Fractions by: Staff The question: four fifths of a dollar is how many cents? The answer: Think about it this way. If you had an apple, and I asked you for one fifth of your apple, what would you do? You would cut the apple into five equal pieces (fifth = five). Then you would give me only one of the five pieces (one fifth means one of the five pieces). We can apply the same idea to your dollar. You want four fifths of a dollar. First, divide the dollar into five equal parts (fifth = five). (I’m going to change the dollar into pennies to make the process a little more visual.) One dollar equals 100 pennies. Divide the pile of 100 pennies into five equal (fifth = five) piles. When 100 pennies is divided into five equal piles of pennies, each of the five smaller piles will have exactly 20 pennies. Pile 1: 20 pennies Pile 2: 20 pennies Pile 3: 20 pennies Pile 4: 20 pennies Pile 5: 20 pennies Total: 100 pennies (one dollar) The dollar is now in five equal parts (fifth = five), just like the first example with the apple. Four fifths of the dollar simply means 4 of the 5 piles: Pile 1: 20 pennies Pile 2: 20 pennies Pile 3: 20 pennies Pile 4: 20 pennies Total: 80 pennies (80 cents) A faster way to compute the answer: Four fifths of a dollar means four fifths multiplied by one dollar (the word “of” means multiply). Four fifths of a dollar = (4/5) * \$1 (4/5) * \$1 = (4/5) * 100 pennies (4/5) * 100 pennies = (4/5) * (100/1) (4/5) * (100/1) = (4 * 100)/(5 * 1) (4 * 100)/(5 * 1) = 400/5 400/5 = 80 The final answer is 80 cents. Thanks for writing. Staff www.solving-math-problems.com