Equivalent fractions – multiplying top and bottom, with a game

MathematicsNumbers & ArithmeticAges 11–12

Split a circle or a long bar into equal parts and shade some of them to make a fraction, then multiply both the numerator and the denominator by 1, 2, 3 or 4 to see that the new fraction still shades the same area. A draggable point on the number line changes the numerator, and a strip of four thumbnails shows four ways of writing the same fraction at once. The Game screen has 3 levels: match pictures with numbers, compare two fractions on a balance scale, and find the missing number that makes two fractions equal. Based on the "Fractions: Equality" simulation by PhET Interactive Simulations, University of Colorado Boulder (CC BY 4.0); rewritten.

Lesson: Equivalent fractions and the fundamental property of fractions