Find the GCD OF 121, 151 And 211

Look at these numbers and take an educated guess as to what the GCD is.

Can you think of any number that would be a common divisor of any of these numbers? Nope.
The GCD is 1. Lonely numbers usually have a GCD of 1.

A good idea for the student learning GCD, LCD, GCF, etc. is to find or make charts of numbers. This makes learning these concepts so much easier.
Get a few friends together to create some. Ask your teacher for advise or help. You'll all of a sudden become really popular in your math class. :)