Alright, let's solve this math problem step by step. First, we have the number 900. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 57. So, we're going to take the number 900 and add it to itself 57 times.
Step 1: 0 + 900 = 900
Step 2: 900 + 900 = 1800
Step 3: 1800 + 900 = 2700
Step 4: 2700 + 900 = 3600
Step 5: 3600 + 900 = 4500
Step 6: 4500 + 900 = 5400
Step 7: 5400 + 900 = 6300
Step 8: 6300 + 900 = 7200
Step 9: 7200 + 900 = 8100
Step 10: 8100 + 900 = 9000
Step 11: 9000 + 900 = 9900
Step 12: 9900 + 900 = 10800
Step 13: 10800 + 900 = 11700
Step 14: 11700 + 900 = 12600
Step 15: 12600 + 900 = 13500
Step 16: 13500 + 900 = 14400
Step 17: 14400 + 900 = 15300
Step 18: 15300 + 900 = 16200
Step 19: 16200 + 900 = 17100
Step 20: 17100 + 900 = 18000
Step 21: 18000 + 900 = 18900
Step 22: 18900 + 900 = 19800
Step 23: 19800 + 900 = 20700
Step 24: 20700 + 900 = 21600
Step 25: 21600 + 900 = 22500
Step 26: 22500 + 900 = 23400
Step 27: 23400 + 900 = 24300
Step 28: 24300 + 900 = 25200
Step 29: 25200 + 900 = 26100
Step 30: 26100 + 900 = 27000
Step 31: 27000 + 900 = 27900
Step 32: 27900 + 900 = 28800
Step 33: 28800 + 900 = 29700
Step 34: 29700 + 900 = 30600
Step 35: 30600 + 900 = 31500
Step 36: 31500 + 900 = 32400
Step 37: 32400 + 900 = 33300
Step 38: 33300 + 900 = 34200
Step 39: 34200 + 900 = 35100
Step 40: 35100 + 900 = 36000
Step 41: 36000 + 900 = 36900
Step 42: 36900 + 900 = 37800
Step 43: 37800 + 900 = 38700
Step 44: 38700 + 900 = 39600
Step 45: 39600 + 900 = 40500
Step 46: 40500 + 900 = 41400
Step 47: 41400 + 900 = 42300
Step 48: 42300 + 900 = 43200
Step 49: 43200 + 900 = 44100
Step 50: 44100 + 900 = 45000
Step 51: 45000 + 900 = 45900
Step 52: 45900 + 900 = 46800
Step 53: 46800 + 900 = 47700
Step 54: 47700 + 900 = 48600
Step 55: 48600 + 900 = 49500
Step 56: 49500 + 900 = 50400
Step 57: 50400 + 900 = 51300

So, 900*57 = 51300