Answer: She used 1/5 of the original melon to make the fruit cup.
Explanation:
Hi, since Mrs Sims cuts the melon in fifths, the whole melon is equal to 5/5.
She gives one piece to each of her four children.
Each piece is 1/5 of the melon.
Since she give 4 = 1/5 x 4 = 4 /5
The leftover is equal to:
5/5-4/5 = 1/5
So, she used 1/5 of the original melon to make the fruit cup.
Feel free to ask for more if needed or if you did not understand something.