Cogito
Grade 2 Math · Chapter 7 · Lesson 7
Bar Graphs
A bar instead of a row of pictures.
10 problems · about 12 minutes · 2.MD.D.10
What this lesson teaches
The child reads and builds a bar graph with a single-unit scale and answers compare questions.
- A bar graph uses a bar instead of many pictures.
- Read the bar against the scale.
- All bars start on the same line.
Warm-Up Review
From earlier lessons. Loosen up before the new work.
3 problemsReview — Picture Graphs: 5 apples and 8 fish. How many more fish?
Answer 3
Why There are 3 more fish.
Review — Money Problems: Pay 75¢ for a 55¢ item. What is the change?
Answer 20
Why The change is 20¢.
Review — Dollars and Cents: How many quarters make one dollar?
Answer 4
Why 4 quarters is $1.
Warm Up
Straightforward practice. Get the method working first.
3 problemsBars of 10 and 6. How many more is the first?
Answer 4
Why The difference is 4.
Why must all the bars start on the same line?
Answer So a taller bar really means more.
Why A shared baseline is what makes the heights comparable.
7 and 5. How many more is the first?
Answer 2
Why 7 − 5.
Build It Up
The same ideas with more to keep track of.
1 problem9, 4 and 6. How many in all?
Answer 19
Why Add all three.
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
3 problems5 and 5. How many more is the first?
Answer 0
Why They are equal.
The Class Survey: A bar graph shows 8 apples and 3 balls. How many more apples?
Answer 5 more
Why There are 5 more apples.
The Total: A bar graph shows 6 apples, 4 balls and 9 fish. How many in all?
Answer 19 things
Why 6 + 4 + 9 = 19.