Depth · one concept from first principles · step 2 of 4

Knowing what 1 cm stands for gives the whole

The bar graph shows the area of Junseo's field planted with each crop. If the corn takes up $85\ \text{m}^2$ , what is the area of the whole field, in $\text{m}^2$ ?

Data & probabilityRatios

Your answer

How to solve

Strategy Analyze the Units — On a bar graph, length and quantity are locked together at a fixed rate. Find what one centimeter is worth, and every other section can be read the same way -- including the whole bar at once.

1STEP 1

Find what one centimeter is worth

The corn's 85 m² is drawn as 5 cm, so divide.

85 ÷ 5 = 17

2STEP 2

Measure the whole bar

The whole field is the five sections laid end to end.

11 + 7 + 5 + 4 + 3 = 30

3STEP 3

Scale the whole bar up

Every centimeter is worth 17 m², so multiply.

30 × 17 = 510

Answer

510 m²

Check the corn's share both ways: 5 out of 30 cm is one sixth, and 510 ÷ 6 = 85 m², the area given.

Takeaway

On a bar graph, work out what one centimeter is worth and the whole graph opens up.

Find what one centimeter is worth
Measure the whole bar
Scale the whole bar up

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