Move the Decimal Point: How Many Times Bigger? - 9314 Toolbox - Move the Decimal Point

You can also open the lesson in a full-screen page. Here is how the lesson is designed.

1. No conclusions, only a lab

Memorising "moving the decimal point one place right multiplies by 10" takes five seconds — forgetting it takes five more. So this lesson never states the rule up front. You get a place-value stage (seven columns from thousands to thousandths), a start number such as 0.35, a target number 35, and two buttons: move left, move right.

Each move physically slides the digit cards: the 3 travels from the tenths column into the ones column. Only after you arrive does the lesson ask: how many times bigger is the new number? Pick from three options — a correct answer completes the level.

2. The wrong options are the point

The distractors are not random. Move 2 places and the options are ×2, ×20 and ×100 — the first two are exactly the classic misconceptions ("2 places means 2 times"). A wrong pick costs nothing: you get one directional line — "2 moves, each one a factor of 10; how do the moves and the multiple relate?" — and you can pick again.

Stuck? Tap the hint button: three levels, one at a time — feel the change by moving, count the moves, then compute the multiple yourself. The hints never contain the final answer.

3. Think first, then open

Before touching the buttons: what is 0.35 with the point moved one place right? And again — how many tens in total? What happens moving back?

Answers: one right gives 3.5 (×10), twice gives 35 (two tens multiplied). Moving back shrinks to 1/10 each time. The reason lives in place value: neighbouring places always differ by a factor of 10, so one move sends every digit into a column worth 10 times more or less.

4. The moment you win

Correct picks trigger confetti, and the banner replays your route: 0.35 → 3.5 → 35, two moves, ×10 each. The move log keeps every level's path. The difficulty slider runs from hardest (8.003 → 8003, three moves) to easiest (0.5 → 50), and levels keep rotating.

FAQ

Why is ×2 or ×20 never right? You move places, and each place is a factor of 10 — this lesson exists to dismantle that shortcut.

What if the point moves past the left edge? The board stops at thousandths; beyond that the rule is unchanged.

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