Let's get this math done. We have 850 and we're going to multiply it by 9. This is the same as taking 850 and adding it to itself 9 times.
Step 1: 0 + 850 = 850
Step 2: 850 + 850 = 1700
Step 3: 1700 + 850 = 2550
Step 4: 2550 + 850 = 3400
Step 5: 3400 + 850 = 4250
Step 6: 4250 + 850 = 5100
Step 7: 5100 + 850 = 5950
Step 8: 5950 + 850 = 6800
Step 9: 6800 + 850 = 7650

So, 850*9 = 7650