A dusk harbor, a teak skiff, and spar buoys marked with integers. Drag left and right to steer. The largest integer is the open channel. Smaller marks swamp the boat. Built for sixth-grade number sense with positives and negatives.
Read the Marks
Two or three spar buoys slide toward the skiff. Each plate shows an integer. Find the largest one — negatives sit below zero.
Steer the Skiff
Drag anywhere on the harbor. The hull slides under your finger. Line up with the largest integer before the marks arrive.
Clear the Gate
A hit lights the lantern and adds 100 points, plus 50 for each step of the streak. A miss rocks the boat and costs a life.
Open the Harbor
Eight clear gates win the run. Three swamps end it. Chase a new best on each difficulty.
Steer the Channel
Buoys drift in from the breakwater. Drag the skiff left or right. When the marks reach the hull, you pass through whichever lane you are in.
Largest Integer Wins
The open channel is always the greatest number in the set. −8 loses to 7. −48 loses to 50. A miss swamps the boat and breaks the streak.
Time on the Water
The marks grow as they approach. You have to decide and move before they hit. Hits surge the hull and throw points off the lantern.
Three Tidelines
Easy uses two close-in buoys and small integers. Medium opens a third channel from −40 to 40. Hard clusters values from −99 to 99.
Spar Buoy is a sixth-grade integer game. A night harbor holds a wooden skiff and approaching numbered buoys. The player steers through the largest integer in each set. That is comparing positives and negatives, shown as a channel instead of a worksheet.
Negatives Have Weight
A plate that reads −55 sits next to 50. Students feel that the larger integer is not the one with the bigger digits.
A Move, Not a Tap
The hull has to be under the right mark when the gate arrives. Reading the set is only half the play.
Instant Wake
A clear channel surges. A wrong mark swamps. Scoring and streak sit on the enamel rail the whole run.
Touch First
The whole harbor is the tiller. Play works with a finger or a mouse. Mute sits on the left, away from the fullscreen control.
The largest integer. If the plates show −48, 50, and −55, the open channel is 50. −48 is greater than −55, but both lose to 50.
Yes, when every mark is negative. Among −9, −2, and −7, the largest is −2. Closest to zero on the positive side of those three.
The skiff snaps to the nearest channel when the marks arrive. Stay lined up under the plate you want.
How many buoys appear, how large the integers get, and how fast they approach. Hard clusters close values so the comparison is tighter.
Sixth and seventh grade (about ages 11–13), when students order positive and negative integers. Stay on Easy to meet small negatives first.