LCM for 7 and 20

What's the Least Common Multiple (LCM) of 7 and 20?

Answer: LCM of 7 and 20 is 140

(One hundred forty)

Finding LCM for 7 and 20 using GCF's of these numbers

The first method to find LCM for numbers 7 and 20 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:

LCM = (Number1 × Number2) ÷ GCF

GCF of numbers 7 and 20 is 1, so

LCM = (7 × 20) ÷ 1

LCM = 140 ÷ 1

LCM = 140

Finding LCM for 7 and 20 by Listing Multiples

The second method to find LCM for numbers 7 and 20 is to list out the common multiples for both nubmers and pick the first which matching:

Multiples of 7: 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98, 105, 112, 119, 126, 133, 140, 147, 154

Multiples of 20: 20, 40, 60, 80, 100, 120, 140, 160, 180

So the LCM for 7 and 20 is 140

Finding LCM for 7 and 20 by Prime Factorization

Another method to find LCM for numbers 7 and 20 is to list all Prime Factors for both numbers and multiply the highest exponent prime factors:

All Prime Factors of 7: 7 (exponent form: 71)

All Prime Factors of 20: 2, 2, 5 (exponent form: 22, 51)

71 × 22 × 51 = 140

See Also

About "Least Common Multiple" Calculator

This calculator will help you find the Least Common Multiple (LCM) of two numbers. For example, it can help you find out what's the Least Common Multiple (LCM) of 7 and 20? (The answer is: 140). Select the first number (e.g. '7') and the second number (e.g. '20'). After that hit the 'Calculate' button.
Least Common Multiple (LCM) also known as the Lowest Common Multiple or Smallest Common Multiple of 2 numbers - it is the smallest positive integer that is divisible by both numbers

LCM Table

Number 1Number 2LCM
12020
22020
320
420
520
620
720
820
920
1020
1120
1220
1320260
1420
1520
1620
1720340
1820
1920380
202020
2120420
2220220
2320460
2420120
2520100
2620260
2720540
2820140
2920580
302060

FAQ

What's the Least Common Multiple (LCM) of 7 and 20?

LCM of 7 and 20 is 140