Question: how to find lcm of two numbers quickly?
Answer: Step 1) Find the GCF for the two numbers. For 18 and 30, GCF is 6.
Step 2) Divide that GCF into either number; it doesn't matter which one you choose, so choose the one that's easier to divide. Choose 18. ... 
Step 3) Take that answer and multiply it by the other number. ... 
Step 4) Celebrate …