The 5 PhET fraction simulators I actually use (and what I pair them with)

Start here. Students drag pizza slices and rectangle blocks into shape outlines that have a target fraction underneath, “build 1/4”, “build 2/3”. The game progresses through levels that quietly get harder.

What makes this sim so good is that it forces students to physically partition the whole themselves. There's no pre-divided shape they pick from; they decide how many parts the whole splits into, then how many of those parts to shade. Kids who can answer “what fraction is shaded?” on a worksheet sometimes can't build “3/4” from a blank rectangle, and this sim surfaces that gap in about ninety seconds.

Use it as a 15-minute independent rotation early in a fractions unit. Walk the room watching for students who shade parts that aren't actually equal in size. That's your next mini- lesson.

Once students can partition a whole, this sim teaches them to read a fraction off a partitioned shape. You set the denominator with a counter, then slide a control to fill the numerator. The fraction notation updates live alongside the shape, circles, horizontal bars, vertical bars, and a number-line representation.

The number-line tab is what makes this sim a keeper. Kids who comfortably write “3/4” for a shaded shape often freeze when asked where 3/4 sits between 0 and 1. The sim makes the connection visible without ever needing you to say it.

Project it on the IWB and run it together as a 10-minute starter. Ask students to predict where 5/6 will land on the number line BEFORE you slide the control. The predictions surface every misconception you'd want to teach into.

This is the gem of the fraction sims. Two fractions sit on opposite sides of a balance scale. Students adjust the numerators and denominators; the scale tips visibly when they aren't equivalent and balances when they are.

Equivalence is the concept primary and lower-secondary students rote-learn most aggressively and understand the least. They'll cheerfully tell you “2/4 equals 1/2” while having no real sense of WHY beyond “you divide both by 2”. This sim makes the WHY concrete, when the visual representations balance, the fractions are the same quantity. Suddenly “equivalent” stops being a procedure and starts being a real property.

The follow-up I always run after this sim is Fracman, a Pac-Man-style game where students eat only the fractions equivalent to a target value. The Equality sim builds the concept; Fracman builds the recognition speed under pressure. Different jobs, both essential.

Game-format consolidation. Students drag fraction representations (shaded shapes, symbolic notation, mixed numbers) onto two pans of a balance, the pans tip when the values don't match, and stay level when they do. Levels ratchet difficulty up; later rounds mix numeric and pictorial representations.

What I like about Fraction Matcher is that it normalises the idea that the same quantity can wear many different costumes, a half-shaded pie, 2/4 written as a symbol, 0.5 if you set the level high enough. Students who can solve equivalence on paper often stumble when the equivalent cards LOOK different. This sim grinds that gap down.

Use it as a 20-minute station rotation after the Equality sim has done the conceptual work. Pair students up, one drags, one explains why the values match or don't. The explanation step is where the deepest learning happens; without it, kids will successfully match by trial-and-error without ever doing the maths.

Same interface as Fractions: Intro, but extended to numerators larger than the denominator. Students see 5/3 visually as one whole shape plus two-thirds of another, the “more than one” concept that breaks so many Year 5 fraction lessons.

The visual proof here is genuinely powerful. Most students reach improper fractions thinking they're some kind of error to be fixed by converting to a mixed number. This sim makes the improper fraction a legitimate representation of a quantity. It's just one whole and a bit, shown directly on a shape. The conversion to mixed number then becomes obvious rather than a procedure to memorise.

Best used in a structured 25-minute lesson: 5 minutes demonstrating, 15 minutes student exploration on devices, 5 minutes reflection where students explain what they noticed.