Money Math

Practice Problems

One of the first things to do with money math is to convert dollars and cents to decimal values.

The numbers to left of the decimal point are the dollars and to the right are the cents. Remember there are 100 cents in every dollar. When adding cents, each 100 cents should be converted to one dollar.

Example Problem 1

Write each of the following in decimal form:

a) Five dollars and twenty-five cents

Answer: $5.25

b) One hundred thirty three dollars and twelve cents

Answer: $133.12

c) 8 dollars and 7 cents

Answer: $8.07

d) 2 dollars and 498 cents

Answer: $6.98

(This was a trick question. You need to take the 400 cents and convert that to 4 dollars.)

Example Problem 2

Add or subtract the following money amounts:

a) $42.75 + $23.12

Answer:

42.75

$65.87

b)$25.05 + $99.99

Answer:

25.05

$125.04

c)$867.55 - $423.71

Answer:

867.55

$443.84

Multiply the following money amounts:

a) $33.15 x 10

Answer:

33.15

$331.50

b)$13.75 x 2

Answer:

13.75

$27.50

When dividing money, you can't really have a fraction of a cent. In most cases you would round up to the nearest cent. In the examples below we have worked them out so they divide to a full cent.

Divide the following money amounts:

a) $100 ÷ 4

Answer: $25

b)$24.50 ÷ 2

Answer: $12.25

To do this answer in your head first divide the dollars in half (24 divided by 2 is 12) then divide the cents in half (50 cents divided by 2 is 25). You get 12 dollars and 25 cents or $12.25.

- Do the dollars and cents separate when adding money. Then put the results together.
- Practice doing problems in your head first, then use a calculator. This will help you when you're out shopping and don't have a calculator available.
- Practice making change with your parents. Count out the bills and coins.
- Dividing money can be helpful when you are out with friends and need to divide up the cost of something like gas for a trip or the price of a pizza.
- To figure a 20% tip, you divide the bill by 5. You can also divide the total by 10 and then multiply that by 2.

Note: This information is not to be used for individual legal, tax, or investment advice. You should always contact a professional financial or tax advisor before making financial decisions.

Math >> Money and Finance