Long Multiplication: 20 × 4
What is 20 × 4?
Answer
20 × 4 and 4 × 20 are the same product — the order of the factors never changes the answer, only the working. Below, 20 is multiplied by 4 in a column, digit by digit.
20 × 4 in a Column
The multiplicand goes on top, the multiplier underneath, both aligned on the right. The multiplier has a single digit, so there is one partial product and the answer goes straight under the line.
| 2 | 0 | |
| × | 4 | |
| 8 | 0 |
Step-by-Step Solution
Step 1: Multiply the multiplicand by the last digit of the multiplier, 4: 20 × 4 = 80.
- 0 × 4 = 0. Write 0.
- 2 × 4 = 8. Write 8.
20 × 4
=80
Check It, and What It Is Not
Check by dividing back. Multiplication and division undo each other, so 80 ÷ 4 = 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 × 4 is a number, not an area. If those are the sides of a room in feet, the answer is 80 square feet — the same arithmetic, a different question, and it is answered by the square footage calculator.
Related Calculations
See Also
- 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--4">20 × 4 = 80 - Long Multiplication - Calculatio</a>