assess students' prior knowledge, ask students to think about the ways
in which they have used ratios, and the type of information they
compared with ratios. This allows you to determine their understanding
Distribute the What's Your Rate? Activity Sheet to each student.
What's Your Rate? Activity Sheet
To begin the lesson, arrange students in pairs. Tell them to choose one of the following activities to do for one minute:
- Say the alphabet repeatedly
- Hop on one foot
- Do jumping jacks
Have one student perform the selected activity while her partner
counts and records the number of times the activity was completed in
one minute. Students can use tally marks or another efficient way of
recording the data.
Have the partners switch roles and repeat the process. On the board,
record the data that each pair has collected. Use only whole numbers.
Disregard any half letters, hops, or jumping jacks.
Ask students: Can you use your data to predict how many times
you can complete the activity in one hour? Point out that this is the
unit rate (per unit). The students should begin to see that with this
data, they can estimate how many times the activity could be done in
other time spans, such as one hour.
Next, discuss the concept of proportion. Define proportion as
two equal ratios. Explain to students that when they write proportions,
they should use a variable in place of the unknown data in the
Example: 30 hops = X hops
1 min. 60 min.
Use examples from the data students gathered to set up
proportions and estimate results for different times. The students
should use the data to practice solving proportions (they can use the
number of times they completed the activity as their unknown).
Check students’ work to make sure they are setting up
proportions consistently, placing the time in the denominators of both
sides of the proportion.