Representing numbers with objects (age 8+)
Draw a scaled picture graph and a scaled bar graph to represent a data set; solve one- and two-step comparison, sum, and difference problems using bar charts, pictograms, and tables
What a learner can do afterwards
- Draw a bar graph where each square represents 5 pets
- From a scaled pictogram, answer: how many more children chose football than tennis?
- Solve a two-step problem: how many votes in total for the top two choices?
The lesson
Sometimes there are too many things to draw one by one on a graph. So the graph uses a key, like 'each square = 5 pets'. The key tells you what one square, block, or picture is really worth. To find the real number, multiply the squares by the key number.
A pictogram shows favourite sports. The key says each ball picture = 2 votes. Football has 4 balls: 4 x 2 = 8 votes. Tennis has 2 balls: 2 x 2 = 4 votes. To find how many more chose football, subtract: 8 - 4 = 4. Four more children chose football than tennis.
Before you read any bar graph or pictogram, look for the key first. If you skip it and just count squares or pictures, your answer will be wrong whenever the key is more than 1.
Find the key, multiply squares or pictures by it, then add or subtract to compare, total, or find the difference.
Watch it
Where it sits
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.