Find the LCM 7 and 28

$7$ and $28$

Step 1

The LCM is the smallest positive number that all of the numbers divide into evenly.

1. List the prime factors of each number.

2. Multiply each factor the greatest number of times it occurs in either number.

Step 2

Since $7$ has no factors besides $1$ and $7$ .

$7$ is a prime number

Step 3

The prime factors for $28$ are $2 \cdot 2 \cdot 7$ .

$28$ has factors of $2$ and $14$ .

$2 \cdot 14$

$14$ has factors of $2$ and $7$ .

$2 \cdot 2 \cdot 7$

Step 4

Multiply $2 \cdot 2 \cdot 7$ .

Multiply $2$ by $2$ .

$4 \cdot 7$

Multiply $4$ by $7$ .

$28$