J's answer to Merlion's Primary 5 Maths Area & Volume Singapore question.

done {{ upvoteCount }} Upvotes
clear {{ downvoteCount * -1 }} Downvotes
J
J's answer
1022 answers (A Helpful Person)
1st
Your first step is correct. ³√512 = 8
Each side of the cube is 8cm long.
Since there are 12 edges in a cube, 12 pieces of 8cm-long ribbon are needed.
Each pack comes with 30cm of ribbon. We must check how many complete pieces we can cut out of 30cm.
30 ÷ 8 = 3 R 6
You can only cut 3 complete pieces out of each pack of 30cm. The remaining 6cm cannot be used or joined together with other 6cm-long pieces to make a new 8-cm piece.
12 pieces ÷ 3 pieces per pack = 4 packs
4 packs are needed.