How to use it in 3 steps
- Enter the dividend, the divisor, and the maximum number of decimal places. You can paste full-width digits or locale-style decimal input.
- Open Options to show the decimal-shift guide, the quotient decimal-point guide, and the transformed equation. Teacher mode adds helper marks and ghost digits so the class can follow why the decimal point moves.
- Press Calculate to refresh the answer, the shift panel, the long-division layout, and the current explanation. Then use Back, Next, or Auto play.
Shortcuts: Alt+S share, Alt+L copy LaTeX, Alt+[ previous step, Alt+] next step.
Examples
Move the decimal point
Long division layout
Current explanation
Step list
Teacher notes
- Pause on the “move both decimal points the same number of places” panel before you let students look at the long-division layout.
- Stop again when the quotient needs a decimal point or when you append 0 so the class can see exactly where decimal division stops matching the whole-number version.
- Pair examples like 1.20 ÷ 0.30 and 1 ÷ 0.3 when you want to compare trailing 0s with continuing into decimal places.
FAQ
Why is it okay to move both decimal points the same number of places?
Because multiplying both the dividend and divisor by the same power of 10 does not change the quotient. It turns the divisor into a whole number so the long division is easier to read.
How many places do I move in 1.20 ÷ 0.30?
Only one place. Even though 0.30 was typed with two decimal places, it is the same value as 0.3, so one shift is enough to make the divisor a whole number.
Where does the decimal point go in the quotient?
If the transformed dividend still has a decimal point, use that position as the guide. If the whole-number part finishes and there is still a remainder, put a decimal point in the quotient before continuing.
Why do I append 0 and keep going?
Because the remainder is not 0 yet. Appending 0 lets you continue into decimal places and get a more complete answer.
How can I check whether the answer is correct?
The panel under the result checks two stages: whether the decimal shift makes sense, and whether multiplying back reaches the original dividend. Exact cases use =, while repeating or truncated views use ≈ so you can tell when the check is only approximate.
Does this page work with negative numbers or fractions?
No. This first version is limited to whole numbers and decimals that are 0 or more.