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 mission3-5 · Guided Lab ShellAdd one to the top and bottom?
Build one half, then add one to the top and the bottom
Add one to the top and bottom?Test my idea
Launch guided mission3-5 · Guided Lab ShellAre these fifths?
Decide whether 2 of 5 unequal pieces make 2/5
Are these fifths?Line it up with equal fifths
Launch guided mission3-5 · Guided Lab ShellWhose piece is bigger?
Compare 1/2 of a small bar with 1/4 of a bar three times as long
Whose piece is bigger?Measure both pieces
Launch guided mission3-5 · Guided Lab ShellTwo names, one amount?
Build 1/2 and 3/6 and test whether two names mean two amounts
Two names, one amount?Test my idea
Launch guided mission3-5 · Guided Lab ShellWhere does 3/4 go?
Decide whether 3/4 has a place on a 0-to-2 number line, then find it
Where does 3/4 go?Cut 0 to 1 into equal jumps
Launch guided mission3-5 · Guided Lab ShellAdd the tops and the bottoms?
Build 1/2 + 1/4 beside 2/6, the add-the-tops-and-bottoms answer
Add the tops and the bottoms?Test my idea
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 mission6-8 · Guided Lab ShellDoes multiplying make it bigger?
Predict 1/2 × 1/3 against 1/3, then take half of the shaded third
Does multiplying make it bigger?Take half of the shaded third
Launch guided mission6-8 · Guided Lab ShellHow many halves fit?
Predict 4 ÷ 1/2, then cut four wholes into halves and count
How many halves fit?Cut and count
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