Question

reflect
alison is sewing a costume and needs $2\frac{3}{8}$ yards of red ribbon, $1\frac{5}{8}$ yards of blue ribbon, and $2\frac{4}{8}$ yards of green ribbon. for each statement below, state whether or not the sum must be regrouped and how you know this. you do not need to find the sum.
yards of red ribbon plus yards of blue ribbon
_____________________
yards of blue ribbon plus yards of green ribbon
_____________________
yards of red ribbon plus yards of green ribbon
_____________________

Explanation:

Step1: Analyze red + blue

Red: $2\frac{3}{8}$, Blue: $1\frac{5}{8}$. Add fractions: $\frac{3}{8}+\frac{5}{8}=\frac{8}{8}=1$. Since fraction sum is 1, regroup (carry over 1 to whole numbers).

Step2: Analyze blue + green

Blue: $1\frac{5}{8}$, Green: $2\frac{4}{8}$. Fractions: $\frac{5}{8}+\frac{4}{8}=\frac{9}{8}=1\frac{1}{8}$. Sum ≥1, so regroup (carry over 1).

Step3: Analyze red + green

Red: $2\frac{3}{8}$, Green: $2\frac{4}{8}$. Fractions: $\frac{3}{8}+\frac{4}{8}=\frac{7}{8}<1$. No regroup needed.

Answer:

• Red + Blue: Must regroup (fraction sum = 1).
• Blue + Green: Must regroup (fraction sum = 9/8 ≥1).
• Red + Green: No regroup (fraction sum = 7/8 <1).