Alright, let's solve this math problem step by step. First, we have the number 820. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 87. So, we're going to take the number 820 and add it to itself 87 times.
Step 1: 0 + 820 = 820
Step 2: 820 + 820 = 1640
Step 3: 1640 + 820 = 2460
Step 4: 2460 + 820 = 3280
Step 5: 3280 + 820 = 4100
Step 6: 4100 + 820 = 4920
Step 7: 4920 + 820 = 5740
Step 8: 5740 + 820 = 6560
Step 9: 6560 + 820 = 7380
Step 10: 7380 + 820 = 8200
Step 11: 8200 + 820 = 9020
Step 12: 9020 + 820 = 9840
Step 13: 9840 + 820 = 10660
Step 14: 10660 + 820 = 11480
Step 15: 11480 + 820 = 12300
Step 16: 12300 + 820 = 13120
Step 17: 13120 + 820 = 13940
Step 18: 13940 + 820 = 14760
Step 19: 14760 + 820 = 15580
Step 20: 15580 + 820 = 16400
Step 21: 16400 + 820 = 17220
Step 22: 17220 + 820 = 18040
Step 23: 18040 + 820 = 18860
Step 24: 18860 + 820 = 19680
Step 25: 19680 + 820 = 20500
Step 26: 20500 + 820 = 21320
Step 27: 21320 + 820 = 22140
Step 28: 22140 + 820 = 22960
Step 29: 22960 + 820 = 23780
Step 30: 23780 + 820 = 24600
Step 31: 24600 + 820 = 25420
Step 32: 25420 + 820 = 26240
Step 33: 26240 + 820 = 27060
Step 34: 27060 + 820 = 27880
Step 35: 27880 + 820 = 28700
Step 36: 28700 + 820 = 29520
Step 37: 29520 + 820 = 30340
Step 38: 30340 + 820 = 31160
Step 39: 31160 + 820 = 31980
Step 40: 31980 + 820 = 32800
Step 41: 32800 + 820 = 33620
Step 42: 33620 + 820 = 34440
Step 43: 34440 + 820 = 35260
Step 44: 35260 + 820 = 36080
Step 45: 36080 + 820 = 36900
Step 46: 36900 + 820 = 37720
Step 47: 37720 + 820 = 38540
Step 48: 38540 + 820 = 39360
Step 49: 39360 + 820 = 40180
Step 50: 40180 + 820 = 41000
Step 51: 41000 + 820 = 41820
Step 52: 41820 + 820 = 42640
Step 53: 42640 + 820 = 43460
Step 54: 43460 + 820 = 44280
Step 55: 44280 + 820 = 45100
Step 56: 45100 + 820 = 45920
Step 57: 45920 + 820 = 46740
Step 58: 46740 + 820 = 47560
Step 59: 47560 + 820 = 48380
Step 60: 48380 + 820 = 49200
Step 61: 49200 + 820 = 50020
Step 62: 50020 + 820 = 50840
Step 63: 50840 + 820 = 51660
Step 64: 51660 + 820 = 52480
Step 65: 52480 + 820 = 53300
Step 66: 53300 + 820 = 54120
Step 67: 54120 + 820 = 54940
Step 68: 54940 + 820 = 55760
Step 69: 55760 + 820 = 56580
Step 70: 56580 + 820 = 57400
Step 71: 57400 + 820 = 58220
Step 72: 58220 + 820 = 59040
Step 73: 59040 + 820 = 59860
Step 74: 59860 + 820 = 60680
Step 75: 60680 + 820 = 61500
Step 76: 61500 + 820 = 62320
Step 77: 62320 + 820 = 63140
Step 78: 63140 + 820 = 63960
Step 79: 63960 + 820 = 64780
Step 80: 64780 + 820 = 65600
Step 81: 65600 + 820 = 66420
Step 82: 66420 + 820 = 67240
Step 83: 67240 + 820 = 68060
Step 84: 68060 + 820 = 68880
Step 85: 68880 + 820 = 69700
Step 86: 69700 + 820 = 70520
Step 87: 70520 + 820 = 71340

So, 820*87 = 71340