PSAT 8/9 Math Practice Test

Multiplication is what “of” usually signals in math language. When we say “one half of a number,” we’re really saying multiply that number by 1/2. “Fifty percent of a number” is 0.5 times the number, and “two-thirds of a group” means two-thirds times the size of the group. In geometry, the area of a rectangle with length and width is the product of those two measurements, which again reflects multiplying the two quantities. Because these common uses map directly to multiplication, that’s the operation represented by “of.” Addition, subtraction, or division are not typically conveyed by the word “of” in standard phrasing; they’re shown with plus, minus, or words like divided by or per.