Solving Subtraction Word Problems Using Variables

The video tutorial explains how to use variables to solve subtraction word problems by writing equations. It introduces the concept of variables as letters representing unknown values and demonstrates this through examples. The tutorial walks through solving problems involving reading pages and lost erasers, emphasizing defining variables, writing equations, and solving for unknowns. It concludes with a method to verify solutions by substituting the variable with the found value.

What is a variable in the context of equations?

• A mathematical operation

• A fixed number

• A type of equation

• A letter representing an unknown value

In the equation 12 - C = 10, what does the variable C represent?

• A mathematical operation

• An unknown value

• The number 10

• The number 12

If you have 237 pages to read and have read 115, how do you represent the pages left to read using a variable?

• 237 + P = 115

• 237 - P = 115

• 115 - P = 237

• P = 237 - 115

What does the variable P stand for in the equation 237 - P = 115?

• The number of days left

• The number of pages left to read

• The number of pages read

• The total number of pages

Lisa started with 27 erasers and now has 15. How do you set up an equation to find out how many she lost?

• E = 27 + 15

• 15 - E = 27

• 27 - E = 15

• 27 + E = 15

In the equation 27 - E = 15, what does E represent?

• The number of erasers Lisa lost

• The total number of erasers

• The number of erasers Lisa started with

• The number of erasers Lisa has now

How can you verify if your solution to an equation is correct?

• By using a different equation

• By guessing the answer

• By substituting the variable with the found value

• By changing the variable