### Home > ACC6 > Chapter 1 Unit 10 > Lesson CC2: 1.1.2 > Problem 1-15

Maria was playing a game with her brother. She said, *“I’m thinking of a number. When you multiply my number by six and add seven, you get twenty-five. What is my number?” *

Find Maria’s number.

How big do you expect her number to be? Can you think of a reasonable number to try?

Pick a reasonable number and try Maria's steps. Let's try

. If Maria multiplies this number ( ) by , she would get . Then, adding , she would get . Can you think of a number that might work better? Try it!

Since

is smaller than , let's choose a bigger number. Let's try . If Maria multiplies by , she would get . Adding , she would get . Since Maria gets by using this number, is the number she described. We now know that Maria's number is

. Explain how you figured out your answer to Maria’s number puzzle.

Can you describe with words the steps that you took to find Maria's number?