Long Multiplication: 100 × 9
What is 100 × 9?
Answer
100 × 9 and 9 × 100 are the same product — the order of the factors never changes the answer, only the working. Below, 100 is multiplied by 9 in a column, digit by digit.
100 × 9 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.
| 1 | 0 | 0 | |
| × | 9 | ||
| 9 | 0 | 0 |
Step-by-Step Solution
Step 1: Multiply the multiplicand by the last digit of the multiplier, 9: 100 × 9 = 900.
- 0 × 9 = 0. Write 0.
- 0 × 9 = 0. Write 0.
- 1 × 9 = 9. Write 9.
100 × 9
=900
Check It, and What It Is Not
Check by dividing back. Multiplication and division undo each other, so 900 ÷ 9 = 100 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.
100 × 9 is a number, not an area. If those are the sides of a room in feet, the answer is 900 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/100--9">100 × 9 = 900 - Long Multiplication - Calculatio</a>