Alright, let's solve this math problem step by step. First, we have the number 915. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 20. So, we're going to take the number 915 and add it to itself 20 times.
Step 1: 0 + 915 = 915
Step 2: 915 + 915 = 1830
Step 3: 1830 + 915 = 2745
Step 4: 2745 + 915 = 3660
Step 5: 3660 + 915 = 4575
Step 6: 4575 + 915 = 5490
Step 7: 5490 + 915 = 6405
Step 8: 6405 + 915 = 7320
Step 9: 7320 + 915 = 8235
Step 10: 8235 + 915 = 9150
Step 11: 9150 + 915 = 10065
Step 12: 10065 + 915 = 10980
Step 13: 10980 + 915 = 11895
Step 14: 11895 + 915 = 12810
Step 15: 12810 + 915 = 13725
Step 16: 13725 + 915 = 14640
Step 17: 14640 + 915 = 15555
Step 18: 15555 + 915 = 16470
Step 19: 16470 + 915 = 17385
Step 20: 17385 + 915 = 18300

So, 915*20 = 18300