Heather solved this problem:
75 is 300% of what number?
A tape diagram. StartFraction part Over whole EndFraction = StartFraction 300 Over 100 EndFraction = StartFraction 75 Over question mark EndFraction. StartFraction part Over whole EndFraction = StartFraction 75 times 4 Over 100 times 4 EndFraction = StartFraction 300 Over 400 EndFraction
What error did Heather make?
None. Her work is correct.
She multiplied 75 and 4 incorrectly.
She should have divided 75 by 4, and divided 100 by 4.
She used the part, 75, to write the percent ratio. The part-to-whole percent ratio is StartFraction 300 Over 100 EndFraction