Playable World missions
Pick one mission. Follow the guide. Submit evidence.
Twenty certified missions span fair sharing, fraction operations, rational expressions, limits, and fractional exponents.
K-2 · Guided Lab Shell · releasedShare the cookies
Give two friends equal cookie shares and check fairness
Share the cookiesShow my choice
Launch guided missionK-2 · Guided Lab ShellShare the pizza
Distribute four equal pizza slices across four friends
Share the pizzaCheck all four shares
Launch guided mission3-5 · Guided Lab Shell · releasedTwo builds, one half
Build one half with two different partitions
Two builds, one halfTest my idea
Launch guided mission3-5 · Guided Lab ShellTwo builds, one third
Build 1/3 and 2/6, then compare their shaded lengths
Two builds, one thirdTest my idea
Launch guided mission3-5 · Guided Lab ShellQuarters and halves
Build 2/4 beside 1/2 and test equivalence
Quarters and halvesTest my idea
Launch guided mission3-5 · Guided Lab ShellWhich is bigger: 1/3 or 1/4?
Compare one third with one fourth using a shared whole
Which is bigger: 1/3 or 1/4?Test my idea
Launch guided mission3-5 · Guided Lab ShellUnit fraction lineup
Order 1/2, 1/3, 1/4, and 1/5 from largest to smallest
Unit fraction lineupCheck the order
Launch guided mission6-8 · Guided Lab Shell · releasedEquivalence via splitting
Split one half into fourths without moving its shaded edge
Equivalence via splittingLock it in and run
Launch guided mission6-8 · Guided Lab ShellCompare 2/3 vs 3/5
Compare 2/3 and 3/5 using exact cross-products
Compare 2/3 vs 3/5Check the cross-products
Launch guided mission6-8 · Guided Lab ShellAdding fractions: 1/4 + 1/3
Rename 1/4 and 1/3 in twelfths before combining
Adding fractions: 1/4 + 1/3Combine the twelfths
Launch guided mission6-8 · Guided Lab ShellFraction times fraction
Overlay 2/3 and 3/4 on a three-by-four area model
Fraction times fractionReveal the overlap
Launch guided mission6-8 · Guided Lab ShellBeyond the unit: 7/4
Count seven fourth-size pieces across two unit bars
Beyond the unit: 7/4Join the two unit bars
Launch guided mission6-8 · Guided Lab ShellMixed numbers and improper fractions
Re-read five third-size pieces across two unit bars
Mixed numbers and improper fractionsJoin the two unit bars
Launch guided mission6-8 · Guided Lab ShellThe add-1-to-top-and-bottom trap
Test whether adding one to numerator and denominator preserves value
The add-1-to-top-and-bottom trapTest the tempting move
Launch guided mission9-12 · Guided Lab Shell · releasedScaling equivalence: proof and boundary
Generalize a visible split into a nonzero scaling argument
Scaling equivalence: proof and boundaryLock it in and run
Launch guided mission9-12 · Guided Lab ShellRational expression equivalence
Probe a rational expression and its simplified form at allowed and excluded inputs
Rational expression equivalenceProbe an x-value
Launch guided mission9-12 · Guided Lab ShellThe cancel-term trap
Find a numerical counterexample to canceling additive terms
The cancel-term trapTest an x-value
Launch guided mission9-12 · Guided Lab ShellThe square-root-2 chase
Squeeze square root of two between neighboring rational bounds
The square-root-2 chaseChoose a precision
Launch guided mission9-12 · Guided Lab ShellIterate to the limit
Iterate the geometric series and track its exact remainder
Iterate to the limitAdd the next term
Launch guided mission9-12 · Guided Lab ShellThe exponent bar
Compare a fractional exponent with division and test the inverse power
The exponent barChoose an x-value
Launch guided mission