OK, let's crack this. We're given 485 and our task is to multiply it by 40. Essentially, we'll be adding 485 to itself 40 times.
Step 1: 0 + 485 = 485
Step 2: 485 + 485 = 970
Step 3: 970 + 485 = 1455
Step 4: 1455 + 485 = 1940
Step 5: 1940 + 485 = 2425
Step 6: 2425 + 485 = 2910
Step 7: 2910 + 485 = 3395
Step 8: 3395 + 485 = 3880
Step 9: 3880 + 485 = 4365
Step 10: 4365 + 485 = 4850
Step 11: 4850 + 485 = 5335
Step 12: 5335 + 485 = 5820
Step 13: 5820 + 485 = 6305
Step 14: 6305 + 485 = 6790
Step 15: 6790 + 485 = 7275
Step 16: 7275 + 485 = 7760
Step 17: 7760 + 485 = 8245
Step 18: 8245 + 485 = 8730
Step 19: 8730 + 485 = 9215
Step 20: 9215 + 485 = 9700
Step 21: 9700 + 485 = 10185
Step 22: 10185 + 485 = 10670
Step 23: 10670 + 485 = 11155
Step 24: 11155 + 485 = 11640
Step 25: 11640 + 485 = 12125
Step 26: 12125 + 485 = 12610
Step 27: 12610 + 485 = 13095
Step 28: 13095 + 485 = 13580
Step 29: 13580 + 485 = 14065
Step 30: 14065 + 485 = 14550
Step 31: 14550 + 485 = 15035
Step 32: 15035 + 485 = 15520
Step 33: 15520 + 485 = 16005
Step 34: 16005 + 485 = 16490
Step 35: 16490 + 485 = 16975
Step 36: 16975 + 485 = 17460
Step 37: 17460 + 485 = 17945
Step 38: 17945 + 485 = 18430
Step 39: 18430 + 485 = 18915
Step 40: 18915 + 485 = 19400

So, 485*40 = 19400