A dusk lagoon, a mango manta, and an ink eel racing for a copper pearl chest. A one-step equation such as x − 20 = 8 sits under the channel. Tap the lantern that is x. A correct stroke surges you forward. A miss lets the eel close in and costs a tank of air. First to the chest wins.
Read the Equation
The plaque shows a one-step equation. Example: x − 20 = 8. Undo the subtraction: add 20 to both sides. x is 28.
Tap That Lantern
Three lanterns float under the plaque. Each shows a candidate value of x. Tap the true one. Keys 1, 2, and 3 also work.
Watch the Race
A correct tap surges the manta forward. A miss lets the eel gain a marker and empties one air tank.
Claim the Chest
First to the last marker wins. If the eel arrives first or your air runs out, the race ends. Chase a new best on Easy, Medium, or Hard.
Race the Channel
You and the eel share an eight-marker course. Correct answers swim the manta toward the chest. Misses advance the eel.
Undo One Step
Every prompt is addition or subtraction with one variable. Easy keeps x on the left. Medium and Hard move x to either side.
Three Lanterns
One lantern is x. The other two are common slips: using the constant, flipping the operation, or off-by-ten.
Air Tanks
Three misses empty your air. Reach the chest first to win. Best pearl scores save per difficulty.
Reef Rush is a sixth-grade pre-algebra race. A dusk lagoon holds a manta and an eel. A one-step addition or subtraction equation sits under the water. The player taps the lantern that equals x. Correct strokes move you toward a pearl chest. Wrong strokes move the rival and cost air. The goal is to reach the chest first.
Inverse Operations First
Students treat + and − as moves they can undo. That is the core habit for later two-step work.
Visible Stakes
The channel is the scoreboard. You see the eel close in. There is no worksheet between the tap and the surge.
Plausible Misses
Wrong lanterns copy the slips sixth graders actually make, so a miss teaches the inverse, not a random number.
Touch First
Lanterns are large. Play sits under the board. The race never hides under a settings overlay.
One-step addition and subtraction with a whole-number x. Easy uses x + a and x − a. Medium and Hard also use a + x and a − x.
The eel surges one marker closer to the chest and you lose one air tank. Three empty tanks or the eel reaching the chest ends the race.
No. Solving the equation is the stroke. The manta swims on its own when you tap the correct lantern.
Where x sits and how large the numbers are. The eight-marker course and the three-air rule stay the same.
Fifth through seventh grade (about ages 10–13), when students meet a variable as a missing number in one-step equations. Stay on Easy for early inverse facts.
x − 20 = 8
Tap the lantern that is x
x + a and x − a. Small numbers.