Players slice blocks of ice and lava into equal parts and drop them onto obstacles so a woolly mammoth can walk past; later levels label the pieces with fractions and ask for matching amounts.
Why it may be useful
Cutting a whole into equal parts, naming them and combining them is the entire mechanic, and a classroom study found it taught fraction concepts as well as a traditional lesson. That is real, though the study was small and short.
It covers early fraction ideas only, is finished in a few hours, and the classroom study behind it was small, so treat the results as promising rather than settled.
Written 2026-09-15 · editorial assessment, not a measured effect · how we rate →
What the game is
Slice Fractions is a phone and tablet puzzle game from Ululab, a small Montreal studio, first released in February 2014. A woolly mammoth needs to walk forward, and blocks of ice and lava are in the way. You draw a line with your finger to cut a block, and the pieces fall under gravity, onto the lava to put it out or off the path to clear it.
There are more than a hundred and forty puzzles, and they are physics puzzles first. The fractions arrive quietly: at first you cut a block into equal parts and use some of them, then labels appear on the pieces, and later a level asks for a stated amount assembled from pieces of different sizes. There is no text anywhere and no narration.
It was built with a pedagogical team from the Université du Québec à Montréal, and it carries an unusual amount of research for a children's app. On the App Store it is a paid download at $3.99 with no ads and no in-app purchases. A School Edition with a teacher guide is sold separately.
What you actually do
Each level is one arrangement to think about before you cut, because a wasted slice usually means restarting. You look at what is blocking the mammoth, decide how many equal parts the block needs, and draw the lines. Then the pieces fall, and either the lava is covered or it is not. Later levels label pieces with fractions and ask you to assemble a stated amount, so a half has to be recognized as two quarters. The difficulty rises by adding one idea at a time: equal parts, then naming them, then comparing them, then adding them together.
What it exercises
Cuts a whole into a stated number of equal parts
Recognizes that two quarters and one half are the same amount
Puts fraction pieces in order by size without measuring
Combines pieces of different sizes to reach a target amount
Plans a cut before making it, because the cut cannot be undone
Why we rate it High Worksheet score 70 / 100
FitHow much real knowledge or skill does the play itself make you use?75weight 45%
Fit is scored 75. The fraction is the move: cutting a whole into equal parts and using some of them is not a lesson wrapped around a game, it is the only action in the game. Symbols arrive after the physical idea rather than before it, which is the right order, and that combination is why the score sits near the top of the scale.
TransferWill what you practise here work outside the game?70weight 30%
Transfer is scored 70, unusually high for us, because a measured result backs it: a classroom study tested fraction items after play and found real gains. The study was short and the sample small, and whether the understanding survives to a written lesson months later is not established, which is what keeps it short of the top.
PracticeDoes the game make you use that skill again and again, as it gets harder?60weight 25%
Practice is scored 60, the weakest of the three by a distance. There are around a hundred and forty puzzles and then it is over, typically within a few hours, and completed levels give no reason to return. It covers early fraction ideas once, well, and stops, so a player who needs sustained practice will need the sequel or something else.
Where it has been used in teaching
Documented cases of this game being used with learners. Each one links to its source.
StudyUniversite du Quebec a Montreal · Primary school · 2016
Researchers at Universite du Quebec a Montreal tested Slice Fractions with third-grade students in Canada; the paper reports pupils who played the game learned fraction concepts as well as those taught with a traditional teacher-led lesson, with evidence the learning transferred.
StudyUniversite du Quebec a Montreal · Primary school · 2019
A follow-up paper by the same Universite du Quebec a Montreal team analyzes the game-design model behind Slice Fractions, building on their earlier classroom testing of the game with elementary students; it focuses on design principles rather than new measured outcomes.
Research-backedPublished research has studied this game, or the exact mechanic it is built on.
The evidence level is Research-backed, meaning a measured outcome exists for this game. Cyr, Charland, Riopel and Bruyere published a classroom study in 2019 in which third-grade pupils played for roughly three hours and their fraction performance was measured; a 2016 conference paper from the same team describes the design. The limits matter: one small study, a short window, and authors who were the developer's own academic partners rather than independent researchers, with no replication. Ululab's press kit and the App Store listing supply the release date, the puzzle count, the price and the absence of ads or in-app purchases.
Editorial assessment - not a measured scientific effect.
Fit
75/100
Transfer
70/100
Practice
60/100
Why it makes the cut
The slicing physics puzzles have real trial-and-error tension and a charming mammoth to help, and the fraction labels arrive as scoring rules rather than lessons.
Research-backed
This is Research-backed: a peer-reviewed classroom study measured fraction learning in third-grade pupils after about three hours of play. It is one small study by the developer's own academic partners, not an independent replication.
Prices are US store listings in USD, last refreshed 2026-09-28; regional prices and sales differ.
A School Edition with all levels unlocked and a teacher guide is sold separately; Slice Fractions 2 continues with fraction multiplication and common denominators.
Age guidance
Ages 6-9
Topics
STEM
Play styles
Single-player, Puzzle
Tags
Fractions · No reading · Short sessions
Cutting a whole into equal parts is the entire mechanic, and a classroom study found real learning after a few hours, though the game is short and covers only the basics.
