Problem
Percent gives the weight of a part
Only part of a fish can be eaten, and a circle graph breaks that edible part down by nutrient. We need the weight of one nutrient.
RatiosData & probability
Your answer
How to solve
Strategy Change Focus / Count the Complement — Two percentages sit in a row here, and they are measured against different wholes. Work out the edible weight first so the graph's percentages have something real to act on.
1STEP 1
Find the edible weight
If 45% cannot be eaten, then 55% can, and that share is taken from the whole fish.
100 - 45 = 55, 160 × 0.55 = 88
88 g of the fish can be eaten.
6.RP.A.3Change Focus Count The ComplementThe edible part weighs .
Why?
The fish is the edible part together with the part that cannot be eaten, and nothing else, so the two shares add to the whole fish.
🧱Whole is the sum of its partsBreak a thing into pieces with no gaps or overlaps and the pieces add back to the whole.
Why?
A percent counts hundredths of the whole, so of the fish's hundred equal pieces are edible.
🧱Multiplication as equal groupsa times b means a equal groups of b — it is just repeated adding of the same amount.
2STEP 2
Find the protein share
The four nutrients fill the circle, so their percentages add to 100.
100 - 70 - 3 - 2 = 25
Protein is 25% of the edible part.
6.SP.B.4Analyze The Units3STEP 3
Apply that share to the edible weight
The graph describes the edible part, so take a quarter of 88 g -- not of the whole fish.
88 × 0.25 = 22
Eating one fish gives 22 g of protein.
6.RP.A.3Organize Information In More WaysAnswer
22 g
Add the edible part back up: water 61.6, protein 22, fat 2.64 and other 1.76 come to 88 g.
Takeaway
Two percentages in a row can have different wholes -- check what each one is measured against.
- Find the edible weight
- Find the protein share
- Apply that share to the edible weight