The value of peter's house has risen 20% a year for the last 3 years. if the value of peter's home 3 years ago was $110,000.00, what is the value now?

Increase $110,000 by 20% 3 times.

110,000 x 0.2 = 22000
(0.2 is 20% as a decimal, we needed to convert it to multiply it)

So we must add 22000 to 110,000, then take 20% of the new cost, and repeat.

Add them
110,000 + 22000 = 132000

Take 20% of new value
132000 x 0.2 = 26400

Add that
132000 + 26400 = 158400

Take another 20% of that
31680

Add them
158400 + 31680 = 190080

So the value is now $190,080

A much more efficient way to do this would be multiplying 1.2 instead of 0.2, and skipping the adding part, as you already took 100% of it and are adding 20% more.

Hope this helps!