Question

show how to multiply 6 * 298 using friendly numbers and then using properties and mental math. write about method you like better and why

Answer 1

6*(298) can be approximated by 6*300=1800.
However, we can easily correct this to get the exact answer in using the distributive properties of multiplication
6*(298)=6*(300-2)=6*300-6*2=1800-12=1788.

Friendly numbers have a mathematical definition (see Wolfram Mathworld) that does not seem to apply here.

If use Shelley Gray's definition of friendly numbers, then it comes to the same as the method of distributive properties.
The next friendly number of 298 is 300, hence we multiply 6 by 300, and subtract the excess of 6*2=12, which evidently also gives 1788.