How to use it in 3 steps
- Enter the top number and the bottom number. You can paste commas, full-width digits, or extra spaces if needed.
- Use the options to show carries, place guides, and shift guides. Teacher mode adds helper marks, ghost cues, and stronger highlights so the class can follow the active row and column.
- Press Calculate to refresh the answer, the written layout, and the step list. Then move step by step or use auto play.
Shortcuts: Alt+S share, Alt+L copy LaTeX, Alt+[ previous step, Alt+] next step.
Examples
Written layout
Step-by-step explanation
Teacher notes
- Start by naming the active row and why each new row begins one place farther left before you discuss the digits inside that row.
- Pause after the partial products are complete and only then move to the final addition so students see the two jobs separately.
- Use examples with a 0 row or an easy shift mistake when you want students to notice what usually goes wrong in the layout.
FAQ
Why do we start one place to the left on the next row?
Because the next digit is in the tens place, hundreds place, or another larger place value. The new row has to begin farther left so the places line up correctly.
When do I carry in long multiplication?
You carry when one multiplication step makes 10 or more. You write the ones digit in the row and keep the extra amount to add into the next step.
What happens when one digit is 0?
That multiplication step becomes 0. The row still follows the same place-value rule, so the layout stays aligned.
How can I check the final answer?
The panel under the result first checks whether the visible partial products add up to the final total. The estimate card does a different job: it tells you whether the size of the answer makes sense, which helps catch shifted rows or missed 0 rows.
Does this page handle decimals or negative numbers?
No. This first version is for whole numbers only, so you can focus on the standard long multiplication layout.