Operations Study Guide: GED Math (page 3)

Practice problems for these concepts can be found at:

Numbers and Operations Practice Problems: GED Math

Choosing an Operation

Often a problem will tell you exactly which operation you should do. However, sometimes you will have to translate the words in a word problem into the operations. Look for these clues when you have to choose the operations.

You add (+) when you are asked to

• find a sum
• find a total
• combine amounts

Key words to look for:

• sum
• total
• all together

You subtract (–) when you are asked to

• find a difference
• take away an amount
• compare quantities

Key words to look for:

• difference
• take away
• how many more than
• how many fewer than
• how much less than
• how much is left over

You multiply (×) when you are asked to

• find a product
• add the same number over and over

Key words to look for:

• product
• times

You divide (÷) when you are asked to

• find a quotient
• split an amount into equal parts

Key words to look for:

• quotient
• per

Examples

1. Add the product of 6 and 3 to the sum of 10 and 4.

To solve this problem, begin by translating the words into math symbols. You know from the list of clues that the word product indicates multiplication. So you will need to multiply 6 and 3. You also know that sum indicates addition.You could write the problem like this: 6 × 3 + 10 + 4.

Now, follow the order of operations. Multiply 6 and 3: 18 + 10 + 4.

Add in order from left to right: 28 + 4 = 32. The answer is 32.

2. Missy and Amy went to a movie at the theater. They shared a large popcorn. Each girl paid for her own drink. The movie cost $6.25. The popcorn cost $4.50. Each drink cost $2. How much did each girl pay?

Begin by translating the words into math symbols. The cost of the popcorn should be divided between the two girls. So, each girl paid the following: $6.25 + ($4.50 ÷ 2) + $2.

Now, follow the order of operations. Do operations in parentheses first: $6.25 + ($2.25) + $2. Add in order from left to right: $8.50 + $2 = $10.50.

Each girl paid $10.50 for the movie and refreshments.