A dusk lock house on a canal. Two chambers share the same number of marks — the denominator. The water fill is the numerator. Yank the brass tiller toward the fuller lock, or leave it in the middle when the fills match. Built for third- and fourth-grade fraction comparison.
Read Both Locks
Each chamber shows a fraction with the same denominator. The stacked water is a strip model of that fraction.
Grab the Tiller
Press the brass knob and drag it left or right. The tiller has to travel far enough to commit.
Send It to the Fuller Side
The lock with more filled cells is larger. If the fills match, release in the middle.
Clear Eight Gates
A good yank scores at once. A miss kicks the tiller back and costs a life. Eight locks win the canal.
A Tiller, Not Two Buttons
You drag a brass tiller across the lock sill. Pull toward the chamber with more water. A weak tug snaps back. That is steering a gate, not tapping a quiz card.
Same Marks, Different Fill
Both locks use the same number of cells. Kids see why 3/5 beats 2/5: the pieces are the same size, and one stack is taller.
Equal Has a Detent
On Hard the chambers can match. Leave the tiller in the middle to set both gates. The center latch is a real third move.
Three Canal Shifts
Easy uses denominators 2–4. Medium runs 5–8 with closer fills. Hard opens 8–12 and sometimes asks for equal.
Sluice Tiller is a third- and fourth-grade game for comparing fractions with like denominators. Two canal locks share the same cell count. The player yanks a tiller toward the chamber with more water, or holds center when the fills are equal. The comparison is something you steer, not a pair of answer buttons.
Strips You Can See
Equal cell sizes make the denominator obvious. The taller stack is the larger fraction.
A Weighted Control
The tiller must travel. A tap in place does nothing. Kids commit with a pull.
Instant Gates
A good set scores at once. A splash is a miss. There is no check-your-work button.
Touch First
The rail is the control. The mute plate sits with the score row, not under the fullscreen button.
Two fractions that share a denominator. 4/6 is larger than 2/6 because more of the same-size pieces are filled. If both show 3/8, they are equal.
Drag the brass tiller toward the fuller chamber and release. To call them equal, leave the tiller in the middle and let go.
The gates splash, the streak resets, and you lose a life. A new pair of locks is dealt if you still have lives.
The denominators and how close the numerators sit. Hard can deal two equal fills. The tiller rule stays the same.
Third and fourth grade (about ages 8–10), when students compare fractions with the same denominator. Stay on Easy for halves, thirds, and fourths.