If you start adding all the way until you find what equals 9, then you multipliy the answer to see if it gets the answer 18.
8+1=9, so you check to see if 8 times 1 equals 18, this doesn't
5+4=9, check 5 times 4 equals 20, this doesn't equal 18
6+3=9, check 6 times 3 equals 18, so 6+3 is your answer!
Hope I helped!
