Problem 8 answer key
The Ore Cart Graph
Grade 3 · Data and probability · Number and operations
MJ 3.4 · C2 · W2
Standard challenge · Moderate workload
About 4–11 minutes
Problem 8: The Ore Cart Graph
1. Find the total
There are 3 + 5 + 2 = 10 cart symbols altogether. Each symbol represents 4 ore blocks:
10 × 4 = 40
All three rows represent 40 ore blocks.
Another correct method is to scale each row first: coal is 12 blocks, iron is 20 blocks, and gold is 8 blocks. Then 12 + 20 + 8 = 40.
2. Compare two rows
The iron row represents 5 × 4 = 20 blocks. The gold row represents 2 × 4 = 8 blocks.
20 − 8 = 12
The graph shows 12 more iron ore blocks than gold ore blocks.