Alright, let's solve this math problem step by step. First, we have the number 125. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 90. So, we're going to take the number 125 and add it to itself 90 times.
Step 1: 0 + 125 = 125
Step 2: 125 + 125 = 250
Step 3: 250 + 125 = 375
Step 4: 375 + 125 = 500
Step 5: 500 + 125 = 625
Step 6: 625 + 125 = 750
Step 7: 750 + 125 = 875
Step 8: 875 + 125 = 1000
Step 9: 1000 + 125 = 1125
Step 10: 1125 + 125 = 1250
Step 11: 1250 + 125 = 1375
Step 12: 1375 + 125 = 1500
Step 13: 1500 + 125 = 1625
Step 14: 1625 + 125 = 1750
Step 15: 1750 + 125 = 1875
Step 16: 1875 + 125 = 2000
Step 17: 2000 + 125 = 2125
Step 18: 2125 + 125 = 2250
Step 19: 2250 + 125 = 2375
Step 20: 2375 + 125 = 2500
Step 21: 2500 + 125 = 2625
Step 22: 2625 + 125 = 2750
Step 23: 2750 + 125 = 2875
Step 24: 2875 + 125 = 3000
Step 25: 3000 + 125 = 3125
Step 26: 3125 + 125 = 3250
Step 27: 3250 + 125 = 3375
Step 28: 3375 + 125 = 3500
Step 29: 3500 + 125 = 3625
Step 30: 3625 + 125 = 3750
Step 31: 3750 + 125 = 3875
Step 32: 3875 + 125 = 4000
Step 33: 4000 + 125 = 4125
Step 34: 4125 + 125 = 4250
Step 35: 4250 + 125 = 4375
Step 36: 4375 + 125 = 4500
Step 37: 4500 + 125 = 4625
Step 38: 4625 + 125 = 4750
Step 39: 4750 + 125 = 4875
Step 40: 4875 + 125 = 5000
Step 41: 5000 + 125 = 5125
Step 42: 5125 + 125 = 5250
Step 43: 5250 + 125 = 5375
Step 44: 5375 + 125 = 5500
Step 45: 5500 + 125 = 5625
Step 46: 5625 + 125 = 5750
Step 47: 5750 + 125 = 5875
Step 48: 5875 + 125 = 6000
Step 49: 6000 + 125 = 6125
Step 50: 6125 + 125 = 6250
Step 51: 6250 + 125 = 6375
Step 52: 6375 + 125 = 6500
Step 53: 6500 + 125 = 6625
Step 54: 6625 + 125 = 6750
Step 55: 6750 + 125 = 6875
Step 56: 6875 + 125 = 7000
Step 57: 7000 + 125 = 7125
Step 58: 7125 + 125 = 7250
Step 59: 7250 + 125 = 7375
Step 60: 7375 + 125 = 7500
Step 61: 7500 + 125 = 7625
Step 62: 7625 + 125 = 7750
Step 63: 7750 + 125 = 7875
Step 64: 7875 + 125 = 8000
Step 65: 8000 + 125 = 8125
Step 66: 8125 + 125 = 8250
Step 67: 8250 + 125 = 8375
Step 68: 8375 + 125 = 8500
Step 69: 8500 + 125 = 8625
Step 70: 8625 + 125 = 8750
Step 71: 8750 + 125 = 8875
Step 72: 8875 + 125 = 9000
Step 73: 9000 + 125 = 9125
Step 74: 9125 + 125 = 9250
Step 75: 9250 + 125 = 9375
Step 76: 9375 + 125 = 9500
Step 77: 9500 + 125 = 9625
Step 78: 9625 + 125 = 9750
Step 79: 9750 + 125 = 9875
Step 80: 9875 + 125 = 10000
Step 81: 10000 + 125 = 10125
Step 82: 10125 + 125 = 10250
Step 83: 10250 + 125 = 10375
Step 84: 10375 + 125 = 10500
Step 85: 10500 + 125 = 10625
Step 86: 10625 + 125 = 10750
Step 87: 10750 + 125 = 10875
Step 88: 10875 + 125 = 11000
Step 89: 11000 + 125 = 11125
Step 90: 11125 + 125 = 11250

So, 125*90 = 11250