OK, let's work through this together. We're starting with 900 and we're going to multiply it by 148, which means we add 900 to itself 148 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
Step 58: 51300 + 900 = 52200
Step 59: 52200 + 900 = 53100
Step 60: 53100 + 900 = 54000
Step 61: 54000 + 900 = 54900
Step 62: 54900 + 900 = 55800
Step 63: 55800 + 900 = 56700
Step 64: 56700 + 900 = 57600
Step 65: 57600 + 900 = 58500
Step 66: 58500 + 900 = 59400
Step 67: 59400 + 900 = 60300
Step 68: 60300 + 900 = 61200
Step 69: 61200 + 900 = 62100
Step 70: 62100 + 900 = 63000
Step 71: 63000 + 900 = 63900
Step 72: 63900 + 900 = 64800
Step 73: 64800 + 900 = 65700
Step 74: 65700 + 900 = 66600
Step 75: 66600 + 900 = 67500
Step 76: 67500 + 900 = 68400
Step 77: 68400 + 900 = 69300
Step 78: 69300 + 900 = 70200
Step 79: 70200 + 900 = 71100
Step 80: 71100 + 900 = 72000
Step 81: 72000 + 900 = 72900
Step 82: 72900 + 900 = 73800
Step 83: 73800 + 900 = 74700
Step 84: 74700 + 900 = 75600
Step 85: 75600 + 900 = 76500
Step 86: 76500 + 900 = 77400
Step 87: 77400 + 900 = 78300
Step 88: 78300 + 900 = 79200
Step 89: 79200 + 900 = 80100
Step 90: 80100 + 900 = 81000
Step 91: 81000 + 900 = 81900
Step 92: 81900 + 900 = 82800
Step 93: 82800 + 900 = 83700
Step 94: 83700 + 900 = 84600
Step 95: 84600 + 900 = 85500
Step 96: 85500 + 900 = 86400
Step 97: 86400 + 900 = 87300
Step 98: 87300 + 900 = 88200
Step 99: 88200 + 900 = 89100
Step 100: 89100 + 900 = 90000
Step 101: 90000 + 900 = 90900
Step 102: 90900 + 900 = 91800
Step 103: 91800 + 900 = 92700
Step 104: 92700 + 900 = 93600
Step 105: 93600 + 900 = 94500
Step 106: 94500 + 900 = 95400
Step 107: 95400 + 900 = 96300
Step 108: 96300 + 900 = 97200
Step 109: 97200 + 900 = 98100
Step 110: 98100 + 900 = 99000
Step 111: 99000 + 900 = 99900
Step 112: 99900 + 900 = 100800
Step 113: 100800 + 900 = 101700
Step 114: 101700 + 900 = 102600
Step 115: 102600 + 900 = 103500
Step 116: 103500 + 900 = 104400
Step 117: 104400 + 900 = 105300
Step 118: 105300 + 900 = 106200
Step 119: 106200 + 900 = 107100
Step 120: 107100 + 900 = 108000
Step 121: 108000 + 900 = 108900
Step 122: 108900 + 900 = 109800
Step 123: 109800 + 900 = 110700
Step 124: 110700 + 900 = 111600
Step 125: 111600 + 900 = 112500
Step 126: 112500 + 900 = 113400
Step 127: 113400 + 900 = 114300
Step 128: 114300 + 900 = 115200
Step 129: 115200 + 900 = 116100
Step 130: 116100 + 900 = 117000
Step 131: 117000 + 900 = 117900
Step 132: 117900 + 900 = 118800
Step 133: 118800 + 900 = 119700
Step 134: 119700 + 900 = 120600
Step 135: 120600 + 900 = 121500
Step 136: 121500 + 900 = 122400
Step 137: 122400 + 900 = 123300
Step 138: 123300 + 900 = 124200
Step 139: 124200 + 900 = 125100
Step 140: 125100 + 900 = 126000
Step 141: 126000 + 900 = 126900
Step 142: 126900 + 900 = 127800
Step 143: 127800 + 900 = 128700
Step 144: 128700 + 900 = 129600
Step 145: 129600 + 900 = 130500
Step 146: 130500 + 900 = 131400
Step 147: 131400 + 900 = 132300
Step 148: 132300 + 900 = 133200

So, 900*148 = 133200