Worksheet Grade 3 Math
Three Wells at Blue Heron Farm: A Scaled Bar Graph Worksheet
A grade 3 worksheet where students draw a scaled bar graph of three farm wells' pumping rates and answer comparison questions using the graph.
Objectives
- Students will draw a scaled bar graph to represent a data set of well pumping rates.
- Students will solve one- and two-step comparison problems using information from a scaled bar graph.
Vocabulary
Key words: scaled bar graph, scale, combined, gallons per minute
Teacher overview
The fictional Blue Heron Farm has three wells that pump water to its fields: Well A pumps 12 gallons per minute, Well B pumps 18 gallons per minute, and Well C pumps 8 gallons per minute. This worksheet has students turn that data into a scaled bar graph and then answer comparison questions using it. A common misconception is counting bar symbols one-for-one with the actual amount instead of multiplying or dividing by the scale; when each symbol stands for 2 gallons per minute, a bar of 6 symbols represents 12 gallons per minute, not 6.
Student Worksheet
Blue Heron Farm has three wells. Each well pumps water to the fields.
| Well | Gallons per minute |
|---|---|
| A | 12 |
| B | 18 |
| C | 8 |
Draw a bar graph. Use 1 symbol for every 2 gallons per minute. Make one bar for Well A, one for Well B, and one for Well C.
How many symbols long is Well A's bar?
How many symbols long is Well B's bar?
How many symbols long is Well C's bar?
How many more gallons per minute does Well B pump than Well C?
How many fewer gallons per minute does Well C pump than Well A?
Well A and Well C run at the same time. How many gallons per minute do they pump in all?
The farm needs 25 gallons per minute. Only Well A and Well C run. Is that enough water? If not, how many gallons per minute are missing?
Well D is a new well. It pumps twice as much as Well C. How many gallons per minute does Well D pump? How many symbols long is its bar?
Why is a scale of 2 gallons per symbol easier to use than a scale of 1 gallon per symbol here? Write one or two sentences.
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Answer Key
Answer: Well A: 6 symbols, Well B: 9 symbols, Well C: 4 symbols.
Each well's rate is divided by the scale of 2 gallons per symbol: 12 ÷ 2 = 6, 18 ÷ 2 = 9, and 8 ÷ 2 = 4.Answer: 6 symbols.
Well A pumps 12 gallons per minute, and 12 ÷ 2 = 6 symbols.Answer: 9 symbols.
Well B pumps 18 gallons per minute, and 18 ÷ 2 = 9 symbols.Answer: 4 symbols.
Well C pumps 8 gallons per minute, and 8 ÷ 2 = 4 symbols.Answer: 10 gal/min.
Well B pumps 18 gallons per minute and Well C pumps 8: 18 − 8 = 10 gallons per minute more.Answer: 4 gal/min.
Well A pumps 12 gallons per minute and Well C pumps 8: 12 − 8 = 4 gallons per minute fewer.Answer: 20 gal/min.
Well A (12) plus Well C (8): 12 + 8 = 20 gallons per minute combined.Answer: short by 5 gal/min.
Wells A and C together pump 20 gallons per minute (from item 7), and the system needs 25: 25 − 20 = 5 gallons per minute short.Answer: 16 gal/min, 8 symbols.
Double Well C's rate: 8 × 2 = 16 gallons per minute. On the scaled graph, 16 ÷ 2 = 8 symbols.Answer: A scale of 2 needs fewer symbols.
With rates of 12, 18, and 8 gallons per minute, a scale of 1 gallon per symbol would need 12, 18, and 8 symbols in each bar, which is harder to draw and count than 6, 9, and 4 symbols with a scale of 2.
Differentiation
Support (below grade level)
Provide a grid with the correct number of boxes already outlined for each bar, so students only need to fill in symbols rather than count out the boxes themselves. Allow students to use a division chart or skip-count by 2s to find each symbol count.
Extension (above grade level)
Ask students to redraw the same graph using a scale of 4 gallons per symbol instead of 2, and explain why Well C's rate of 8 gallons per minute still makes a bar of whole symbols at the new scale, while a rate that does not divide evenly by 4, such as 10, would need part of a symbol.
ELL supports
Pre-teach "scale," "combined," and "symbol" using a simple key card that shows one symbol equals 2 gallons per minute, displayed next to a worked example. Allow students to answer items 5 through 8 by circling the correct number on a provided list of choices instead of writing the full number sentence.