Mr. R.’s World of Math

Lesson: Window Washers
Grade Level: 3 to 5
Skills: Subtraction, addition, division

Exemplar:
You’ve just been hired as a window washer for the world’s tallest building. The building has 209 floors. That’s a lot of washing you have to do!!!
You decide to start washing windows from the top floor and work your way down.

You’re able to wash 19 floors a day.

How many days is it going to take you to wash the windows on every floor of the building?

Challenge:
How many (whole) days would it take, if you wash windows on only 14 floors each day?