Alright, let's solve this math problem step by step. First, we have the number 990. 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 990 and add it to itself 57 times.
Step 1: 0 + 990 = 990
Step 2: 990 + 990 = 1980
Step 3: 1980 + 990 = 2970
Step 4: 2970 + 990 = 3960
Step 5: 3960 + 990 = 4950
Step 6: 4950 + 990 = 5940
Step 7: 5940 + 990 = 6930
Step 8: 6930 + 990 = 7920
Step 9: 7920 + 990 = 8910
Step 10: 8910 + 990 = 9900
Step 11: 9900 + 990 = 10890
Step 12: 10890 + 990 = 11880
Step 13: 11880 + 990 = 12870
Step 14: 12870 + 990 = 13860
Step 15: 13860 + 990 = 14850
Step 16: 14850 + 990 = 15840
Step 17: 15840 + 990 = 16830
Step 18: 16830 + 990 = 17820
Step 19: 17820 + 990 = 18810
Step 20: 18810 + 990 = 19800
Step 21: 19800 + 990 = 20790
Step 22: 20790 + 990 = 21780
Step 23: 21780 + 990 = 22770
Step 24: 22770 + 990 = 23760
Step 25: 23760 + 990 = 24750
Step 26: 24750 + 990 = 25740
Step 27: 25740 + 990 = 26730
Step 28: 26730 + 990 = 27720
Step 29: 27720 + 990 = 28710
Step 30: 28710 + 990 = 29700
Step 31: 29700 + 990 = 30690
Step 32: 30690 + 990 = 31680
Step 33: 31680 + 990 = 32670
Step 34: 32670 + 990 = 33660
Step 35: 33660 + 990 = 34650
Step 36: 34650 + 990 = 35640
Step 37: 35640 + 990 = 36630
Step 38: 36630 + 990 = 37620
Step 39: 37620 + 990 = 38610
Step 40: 38610 + 990 = 39600
Step 41: 39600 + 990 = 40590
Step 42: 40590 + 990 = 41580
Step 43: 41580 + 990 = 42570
Step 44: 42570 + 990 = 43560
Step 45: 43560 + 990 = 44550
Step 46: 44550 + 990 = 45540
Step 47: 45540 + 990 = 46530
Step 48: 46530 + 990 = 47520
Step 49: 47520 + 990 = 48510
Step 50: 48510 + 990 = 49500
Step 51: 49500 + 990 = 50490
Step 52: 50490 + 990 = 51480
Step 53: 51480 + 990 = 52470
Step 54: 52470 + 990 = 53460
Step 55: 53460 + 990 = 54450
Step 56: 54450 + 990 = 55440
Step 57: 55440 + 990 = 56430

So, 990*57 = 56430