Representing Equations in Word Problems

This lesson covers writing equations to represent real-world situations. It explains how to use variables to denote unknowns and provides examples of modeling problems using equations. The lesson also discusses the structure of equations, including the placement of coefficients and the commutative property of multiplication. Students learn to write and solve equations from word problems, using different strategies to find solutions.

What is the purpose of using a model when writing equations for real-world situations?

• To make the problem more complex

• To organize information and simplify the problem

• To confuse the reader

• To eliminate the need for variables

Why are lowercase 'l' and 'o' typically not used as variables?

• They are reserved for constants

• They are too common

• They can be confused with numbers

• They are difficult to write

If Sophia earned $30 by walking a dog for an unknown number of hours at $10 per hour, how can you represent the number of hours she worked?

• 30 * 10 = H

• 30 / 10 = H

• 30 - 10 = H

• 30 + 10 = H

Dave planted 36 tulip bulbs, 16 of which are red. How can you find the number of yellow tulips?

• 16 - 36 = Y

• 36 - 16 = Y

• 36 + 16 = Y

• 16 + Y = 36

Bob is B years old, and his brother is half his age. How can you represent the brother's age?

• B * 2

• B / 2

• B - 2

• B + 2

Tala read 80 pages of a 135-page book. How can you represent the number of pages she has left to read?

• P + 135 = 80

• 80 + P = 135

• 135 - 80 = P

• 80 - P = 135

A number multiplied by five equals 40. How can you represent this equation?

• 5 / n = 40

• n - 5 = 40

• n + 5 = 40

• 5n = 40

28 divided by a number equals four. How can you represent this equation?

• 28 * n = 4

• 28 / n = 4

• n / 28 = 4

• 28 + n = 4

If 6 times a number divided by 2 equals 9, how can you represent this equation?

• 6 / n * 2 = 9

• 6 + n / 2 = 9

• 6 - n / 2 = 9

• 6n / 2 = 9

25 less than a number equals 50. How can you represent this equation?

• n + 25 = 50

• n * 25 = 50

• n - 25 = 50

• 25 - n = 50