Put the digits on the right rung — km down to mm — and read the answer straight off the ladder.
Every metric unit is one rung on a ladder: kilo, hecto, deca, the base unit, deci, centi, milli. Step down a rung and the number grows ten times. Step up and it shrinks ten times.
Kids place digits on the rungs, read the value back, convert between units, then add and subtract mixed quantities — the same ladder the whole way through. Free, no login, works for length, mass, and capacity.
Tap a box, then tap a number on the pad. The next box lights up on its own, so you can type a whole row without stopping.
Press Check Answer when the row is done. Boxes that are wrong turn red and stay filled — fix those, then check again. Ten correct problems finish the level.
Some levels open with a walkthrough. Tap Next to watch each step, then Start Practice to try it yourself. Show Steps brings the walkthrough back any time.
Levels 1–4: place one, two, and three digits on the ladder.
Level 5: read a filled ladder back as a number.
Levels 6–8: convert one unit into another, both directions.
Levels 9–10: write mixed units two ways, and split a total back apart.
Levels 11–13: add and subtract mixed units, with carrying and borrowing.
Level 14: Mixed Review — every kind of problem, no hints.
By the end of the ladder a child can:
• Name the metric prefixes in order and say what each step does to a number.
• Convert a whole quantity between any two units of length, mass, or capacity.
• Write a mixed quantity such as 3 m 4 cm as a single number in one unit.
• Add and subtract mixed quantities, carrying and borrowing across units.
• Split a total back into two units.
Matches the NCERT Class 3–5 measurement strand.
Level 1
Great job!