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.
675 + 675 + 8.375 = 9.725. The 675 values are lined up with the 375 portion of 8.375.
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.
675 + 675 + 8.375 = 9.725. The 675 values are lined up with the 375 portion of 8.375.
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.
Answers
GPT-4o mini
Ming's error lies in how she aligned and added the decimal values. The correct explanation is:
**She should have included the decimal in 6.75 and aligned the decimal points to add 6.750 + 6.750 + 8.375 = 21.875.**
By not aligning the decimal points properly, she miscalculated the total. When done correctly, the addition yields the accurate total of 21.875, not 9.725.
**She should have included the decimal in 6.75 and aligned the decimal points to add 6.750 + 6.750 + 8.375 = 21.875.**
By not aligning the decimal points properly, she miscalculated the total. When done correctly, the addition yields the accurate total of 21.875, not 9.725.