Alright, let's solve this math problem step by step. First, we have the number 407. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 42. So, we're going to take the number 407 and add it to itself 42 times.
Step 1: 0 + 407 = 407
Step 2: 407 + 407 = 814
Step 3: 814 + 407 = 1221
Step 4: 1221 + 407 = 1628
Step 5: 1628 + 407 = 2035
Step 6: 2035 + 407 = 2442
Step 7: 2442 + 407 = 2849
Step 8: 2849 + 407 = 3256
Step 9: 3256 + 407 = 3663
Step 10: 3663 + 407 = 4070
Step 11: 4070 + 407 = 4477
Step 12: 4477 + 407 = 4884
Step 13: 4884 + 407 = 5291
Step 14: 5291 + 407 = 5698
Step 15: 5698 + 407 = 6105
Step 16: 6105 + 407 = 6512
Step 17: 6512 + 407 = 6919
Step 18: 6919 + 407 = 7326
Step 19: 7326 + 407 = 7733
Step 20: 7733 + 407 = 8140
Step 21: 8140 + 407 = 8547
Step 22: 8547 + 407 = 8954
Step 23: 8954 + 407 = 9361
Step 24: 9361 + 407 = 9768
Step 25: 9768 + 407 = 10175
Step 26: 10175 + 407 = 10582
Step 27: 10582 + 407 = 10989
Step 28: 10989 + 407 = 11396
Step 29: 11396 + 407 = 11803
Step 30: 11803 + 407 = 12210
Step 31: 12210 + 407 = 12617
Step 32: 12617 + 407 = 13024
Step 33: 13024 + 407 = 13431
Step 34: 13431 + 407 = 13838
Step 35: 13838 + 407 = 14245
Step 36: 14245 + 407 = 14652
Step 37: 14652 + 407 = 15059
Step 38: 15059 + 407 = 15466
Step 39: 15466 + 407 = 15873
Step 40: 15873 + 407 = 16280
Step 41: 16280 + 407 = 16687
Step 42: 16687 + 407 = 17094

So, 407*42 = 17094