Long Multiplication Calculator

Long Multiplication Calculator

Multiply two whole numbers step by step and review the partial products used in long multiplication.

Last updated: June 2026 | By Patchworkr Team

Long Multiplication Solver
Total Product
5535
123 × 45 = 5535
Visual Breakdown
1
2
3
×
4
5
615
4920
5535

What Is Long Multiplication?

Long multiplication multiplies a number by each digit of the other number, then adds the shifted partial products together.

How to Multiply by Hand

  1. Write the multiplicand above the multiplier.
  2. Multiply by each digit of the multiplier from right to left.
  3. Shift each partial product one place left for every new digit.
  4. Add the partial products to get the final answer.
partial products + shifts

Worked Example

123 × 45 = 5535

123 × 45 = 5535

Frequently Asked Questions

Does the tool accept decimals?

No. This visualizer is for whole numbers only because the step display is digit-based.

What if the numbers have different lengths?

That is fine. The shorter side is treated as if it has leading zeros.

Why reject non-digits?

Malformed characters are rejected so the calculator does not silently change the math.

Can I multiply very large numbers?

Yes. The total uses BigInt, so large whole-number products remain exact.

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