Long Multiplication: 20 × 20
What is 20 × 20?
Answer
20 × 20 is a square: a number multiplied by itself, so 400 is the square of 20. Below, 20 is multiplied by 20 in a column, digit by digit.
20 × 20 in a Column
The multiplicand goes on top, the multiplier underneath, both aligned on the right. Only one digit of the multiplier is not zero, and it stands for 20, so there is a single partial product and the answer goes straight under the line.
| 2 | 0 | ||
| × | 2 | 0 | |
| 4 | 0 | 0 |
Step-by-Step Solution
Step 1: The last digit of the multiplier is 0, so this partial product is 0 and adds nothing to the total.
Step 2: The next digit of the multiplier is 2, and it stands for 20: 20 × 20 = 400.
- 0 × 2 = 0. Write 0.
- 2 × 2 = 4. Write 4.
20 × 20
=400
Check It, and What It Is Not
Check by dividing back. Multiplication and division undo each other, so 400 ÷ 20 = 20 must come out exactly, with no remainder.
Fractions are a different calculation. Both factors here are whole numbers; for 2/3 or 2 3/4 use the fraction multiplication calculator, which multiplies numerators and denominators separately.
20 × 20 is a number, not an area. If those are the sides of a room in feet, the answer is 400 square feet — the same arithmetic, a different question, and it is answered by the square footage calculator.
Related Calculations
See Also
- Times Table Chart - Any number from 1 to 100, rows from ×1 to ×12
- Long Division Calculator - Step-by-step long division with detailed explanation
- Multiplying Fractions Calculator - Multiply fractions, mixed numbers and whole numbers step by step
- Factors of a Number - List all Factors and Factor Pairs of a Number
- Greatest Common Factor - Find the Greatest Common Factor (GCF) of two numbers
- Least Common Multiple - Find the Least Common Multiple (LCM) of two numbers
<a href="https://calculat.io/en/number/long-multiplication/20--20">20 × 20 = 400 - Long Multiplication - Calculatio</a>