Intermath | Workshop Support

 Write-up

Title
Lucky Find

Problem Statement
Karen found \$2 on the sidewalk. "Wow!" said Karen. "Now I have five times as much as I would have had if I had lost \$2!" How much money did Karen have before she found the \$2?

Problem setup

Determine the original amount of money Karen possessed.  If she adds \$2 to her original amount, she now has 5 times more than she would have if she had lost \$2.

Plans to Solve/Investigate the Problem

Think of an equation.  After finding \$2, her amount is equal to 5 times what she would have had if \$2 were lost.

Investigation/Exploration of the Problem

x = original amount

Set up equation:

Original amount  + amount found = 5 times (original amount – amount lost)

x + \$2 = 5 (x - \$2)

Solve equation:           x + 2   =  5x -10

+10  =  -x

12  =  4x

3  =  x

Check solution:           3 + 2   =  5 (3 – 2)

5   =  5 (1)

5   =  5

Author & Contact
LLaster
llaster@rockdale.k12.ga.us

Link(s) to resources, references, lesson plans, and/or other materials