Definition
Multiplicative comparison
A multiplicative comparison uses a multiplier to relate one amount to a reference amount.
What it means
First identify the reference amount—the amount being copied. Then ask how many copies make the other amount. If one jar holds 5 shells and another holds 20, the second jar has 4 times as many because 4 × 5 = 20. The direction matters: 20 is 4 times 5, while 5 is one quarter of 20.
Remember it
Ask, “How many copies of the reference amount make the other amount?”
Example
A short ribbon is 7 cm long and a long ribbon is 28 cm long. Calculate 28 ÷ 7 = 4. The long ribbon is 4 times as long as the short ribbon, represented by 28 = 4 × 7.
Watch for
“The long ribbon is 21 cm longer” is an additive comparison. “The long ribbon is 4 times as long” is a multiplicative comparison.
Common mix-up
Name the reference quantity before dividing; reversing the reference reverses the comparison.
Exact meaning
A multiplicative comparison relates two quantities by a multiplier: one quantity equals a stated number of copies of a reference quantity. It compares by “times as much” or “times as many,” not by a fixed additive difference.