Answer:
The dollar bill and a penny together weigh 3.5 grams or 35 decigrams.
Step-by-step explanation:
The important idea is that you can only add units if they are the same, grams + grams or decigrams + decigrams.
1. Suppose you want the answer in grams so you convert the weight of the penny to grams:
\(25 decigrams*\frac{0.1 grams}{1 decigram} = 2.5 grams \\ 1 gram + 2.5 grams\\3.5 grams\)
2. Suppose you want the answer in decigrams so you convert the weight of the dolar bill to decigrams:
\(1 gram*\frac{10decigrams}{gram} = 10 decigrams \\ 10 decigrams + 25 decigrams\\35 decigrams\).
