Percent Equations

Understand, Write & Solve Percent Equations

Multiple Choice

When plugging in a value for p (the percentage) in the percent equation, you need to write the percent in what form?

• word

• fraction or decimal

• algebraic

• Pig Latin

Example 1: Finding a part of a number

Multiple Choice

Use Example 1 to help you.

Write and Solve an equation for the following:

32% of 25 is what number?

• 32 = 25w

  1.28 = w

• 32 x 25 = w

  800 = w

• 0.32 x 25 = w

  8 = w

• 25w = .32

  w = 128

Multiple Choice

Use Example 1 to help you.

Write and SOLVE and equation for the following:

20% of 150 is what number?

• 0.20 x 150 = a

  30 = a

• 20 x 150 = a

  300 = a

• 20 = 150a

  2/15 = a

• 20a = 150

  a = 7.5

​Example 2: Find a Percent, given a part and a whole

Fill in the Blank

In Example 2, the part (a) is _ .

.

Fill in the Blank

Use Example 2 to help you answer the following:

45 is what percent of 60?

%

Multiple Choice

Use Example 2 to help you.

Write and solve an equation for the following:

29 is what percent of 20?

• 29 x 20 = p

  580% = p

• 29 = 20p

  145% = p

• 29 = 20p

  1.45 = p

• p + 20 = 29

  p = 9%

Fill in the Blank

Use Example 3 to help you.

35% of what number is 35?

Multiple Choice

Use Example 3 to help you.

Write and solve an equation for the following:

0.5% of what number is 12?

• .50 + w = 12

  w = 11.5

• 50w = 12

  w = .24

• 5w = 12

  w = 2.4

• 0.005w = 12

  w = 2400