
2.1 – Two – Term and Three – Term Ratios

2.2 – Rates

2.3 – Proportional Reasoning
 2 to 3
 2:3
 2/3
 2:3:4

Two Term Ratio: compares two
quantities measured in the same
units. Ex. 4 to 5 or 4:5

Three Term Ratio: same thing
except compares three
quantities measured in the same
units.
Ex. 2 to 4 to 6 or 2:4:6

Part-to-Part Ratio – compares different parts
of a group to each other. (Ex. 3 girls to 1 boy)

Part-to-Whole Ratio – compares one part of a
group to the whole. (Ex. 1:4 - one girl to 4
students total)
Two term or three term?





2 cars to 4 trucks
2 black cows to 4 brown cows to 5 white cows
2:6:9
2/56
3:54:109
Part to part or part to whole?

5 boys to 32 total students

3 spruce trees to 4 maple trees to 2 pine trees

3 soccer players to 5 volleyball players

3 hockey players to 20 total athletes

3/7

Example 1 – Counting Marbles

Example 2 – Mixing Juice

Practice Problems
 p. 51-54
 #5 – 10, #14, #17, #19, #20, and #22
Rates – compares two quantities
measured in different units
 List as many rates as you can think of:

72 beats per minute (72bpm)

100 kilometres per hour
(100km/hr)

$8.65/hr

30 gallons per mile
Unit rate – a rate in which the second term is
one. (Ex. 20km/hr or 20km/1 hour)
Speed – a unit rate that compares distance to
time, or distance over time.
* You can figure out the unit rate of a rate by
dividing the first number by the second. For
example 200 km/2 hours = 100 km/hr (a big
help for pricing – unit price)

Example 1 – Unit rate of hummingbirds

Example 2 – Pricing of Orange Juice
Practice Problems
 p.60-62
 # 5, 6, 8, 10, 11, 14, and 17
Proportion – a relationship that says that two
ratios or two rates are equal.

2/3 is proportional to 6/9

$10 per hour for a 7 hour shift is proportional
to $70 for 7 hours of work

Example 1 – Electricity rates

Example 2 – Trout
Practice Problems
 p. 67-69
 #4, 6, 9, 10, 13, 15, 17, 19, 24, and 27