Definition
Comparison
A comparison tells how objects or values are alike, different, greater, less, or equal.
What it means
Decide what you are comparing first. Two boxes can be compared by height, mass, colour, or capacity, but those are different questions. For numerical measures, use compatible units before deciding the relationship.
Remember it
Same question, same unit, then compare.
Example
A green ribbon is 80 cm long. A blue ribbon is 1 m long. Change 1 m to 100 cm, then compare 80 and 100. The green ribbon is shorter because 80 < 100.
Watch for
Fraction comparisons are valid only when the fractions refer to the same whole. One half of a small cake need not be more cake than one third of a much larger cake.
Common mix-up
A comparison needs one chosen attribute: a box can be taller but lighter.
Exact meaning
A mathematical comparison examines two or more objects, quantities, or values using the same stated attribute or compatible unit, then describes their relationship, such as equal to, greater than, less than, longer, or heavier.