Recipe Adjuster

Pre-Algebra · Axiom Academy

Scaling a recipe up or down is one idea: multiply every ingredient by the same scale factor. Here is the original recipe, written for 4 people . Three of the four amounts are fractions of a cup — exactly the kind of number we'll have to multiply. Watch each amount fill its measuring bar; the taller the bar, the more of that ingredient. 2. One Scale Factor for Everything Going from 4 people to 6 isn't "add 2 of each." It's a multiply . First find the scale factor — how many times bigger the new batch is than the old one: the same factor hits every ingredient Now multiply each amount by . Watch all four bars grow on the same beat — flour, butter, chips, and eggs scale up at once , by the same factor. The arithmetic, ingredient by ingredient Each is fraction fraction: — multiply the tops, multiply the bottoms, then reduce. 3. Halve It, Double It — the Balance Holds The scale factor can be bigger than 1 (a bigger batch) or smaller than 1 (a smaller one). Halving means ; doubling means . Watch the bars shrink to half height, then grow to double — and notice that flour always stays the same fraction of the chips. The recipe's proportions never drift. Flour , butter , chips , eggs . Flour-to-chips is in the original. Scale by anything — , 2 , — and the factor cancels, leaving the same ratio . That's exactly why the cookies still taste right at any size. 4. Find the Factor, Then Multiply

This is the written version of the interactive lesson above. See the full Pre-Algebra course.