standard_description: Apply the area and perimeter formulas for rectangles in real world and mathematical problems. For example, find the width of a rectangular room given the area of the flooring and the length, by viewing the area formula as a multiplication equation with an unknown factor.
problem_activity: Task
Jillian says
I know that 20 times 7 is 140 and if I take away 2 sevens that leaves 126. So 126 $\div$ 7 = 18.
Is Jillian's calculation correct? Explain.
Draw a picture showing Jillian's reasoning.
Use Jillian's method to find 222 $\div$ 6.


aligns: no