Question

Please help

The students in Mr. Nottingham’s class are writing expressions for
the perimeter of a rectangle that has a side length of l and a
width of w. They share their answers:
Sergio: 2(l + w)
Jamie: l + w + l + w
Karina: 2l + w
Ethan: 2w + 2l
l
w
l
Finish each sentence by explaining how each student was thinking
about finding the rectangle’s perimeter:
 Sergio’s strategy was to…
 Jamie’s strategy was to…
 Karina’s strategy was to…
 Ethan’s strategy was to…
Which of the students are correct? If a student was incorrect,
explain what they did wrong.

Answer 1

Sergio's strategy was to multiply the sum of the length and width of the rectangle by 2. This was one correct way to find the perimeter of the rectangle.

Jamie's strategy was to add the given measurements of the length and width of the rectangle together. This was another correct way to find the perimeter of the rectangle.

Karina's strategy was to multiply the given length of the rectangle by 2 and add this product to the width of the rectangle. This was NOT a correct way to find the perimeter of the rectangle, as it did not follow the formulas to finding the perimeter of a rectangle: l + w + l + w, or 2(l + w) and furthermore formulas that explain the same thing. Karina only multiplied the length by 2 and did not account for the width of the retangle which she should have done as well.

Ethan's strategy was to multiply the width by 2, multiply the length by 2, and add these two products together to find the perimenter. This final strategy was correct, and can be used to find the perimeter of the rectangle.

Hope this helps you! I love doing math, so enjoy!