Understanding Percentages and Solving for Unknowns

The video tutorial explains how to find the number for which 78 is 15%. It begins by setting up the problem and converting 15% to a decimal (0.15). The tutorial then solves the equation by dividing both sides by 0.15 to find the unknown number, x. A manual calculation is performed to find that 78 divided by 0.15 equals 520. The video concludes by discussing relevant math terminology, such as base and amount, and confirms that 78 is indeed 15% of 520.

What is the unknown number if 78 is 15% of it?

• 520

• 100

• 78

• 15

How can 15% be expressed as a decimal?

• 1.5

• 0.15

• 15

• 0.015

What is the decimal equivalent of 15% used for in the equation?

• To decrease the number

• To increase the number

• To convert to a fraction

• To simplify calculations

Tags

CCSS.HSA.REI.A.1

What operation is used to isolate x in the equation 0.15x = 78?

• Division

• Subtraction

• Multiplication

• Addition

Tags

CCSS.6.EE.B.7

What is the first step in solving the equation 0.15x = 78?

• Add 0.15 to both sides

• Subtract 0.15 from both sides

• Multiply both sides by 0.15

• Divide both sides by 0.15

Tags

CCSS.6.NS.B.3

What is the result of dividing 78 by 0.15?

• 520

• 780

• 52

• 5.2

What is the term for the number you take a percentage of?

• Percent

• Total

• Base

• Amount

Tags

CCSS.6.RP.A.3C

If 15% of a number is 78, what is the percentage called?

• Whole

• Base

• Amount

• Percent

In the context of percentages, what is 78 referred to as?

• Percent

• Amount

• Whole

• Base

Tags

CCSS.7.RP.A.3

Why is it important to understand the terms percent, base, and amount?

• To solve equations faster

• To understand the relationship between numbers

• To memorize formulas

• To avoid using calculators

Tags

CCSS.7.RP.A.3