Ratios
Choose the order of two amounts, express their ratio, and find equivalent ratios.
Meaning
A ratio compares two amounts in a specified order. Multiplying or dividing both terms by the same nonzero number gives an equivalent ratio.
Example
The ratio of 2 red objects to 3 blue ones is 2:3. Doubling both counts to 4 and 6 gives an equivalent ratio. Four red and six blue objects are two copies of a group containing two red and three blue objects. Scaling both counts equally leaves their relative size unchanged. Red:blue and blue:red reverse the order and give different ratios.
Practice for this concept
Scope and references
Topics
Comparing two amounts, ratio notation, ratio values, equivalent ratios
Learning goal
Choose the order of two amounts, express their ratio, and find equivalent ratios.
Helpful background
Check the order of the amounts and common scaling.
Finding quantities in equivalent ratios
Does not include distinguishing proportional allocation from inverse proportionality.