Question

Ming made a triangular picture frame out of cardboard. The sides of the frame are 6.75 in., 6.75 in., and 8.375 in. Ming uses the addition below to determine the amount of string she needs to decorate the edges of the frame. mc012-1.jpg Which explains Ming’s error? She should have included the decimal in 6.75 and aligned the decimal points to add 6.750 + 6.750 + 8.375 = 21.875. She forgot to put the decimal point in two of the numbers: 0.675 + 0.675 + 8.375 = 9.725.. She added 6.75 twice, and she should have only added it once: 6.75 + 8.375 = 15.125. She should have placed a zero placeholder after the decimal point to add 6.075 + 6.075 + 8.375 = 20.525.

Answer 1

I think the answer is that she should have included the decimal in 6.75 and aligned the decimal points to add 6.750 + 6.750 + 8.375 = 21.875.