Let's roll up our sleeves and solve this. We have 520 and we're going to multiply it by 85, essentially adding 520 to itself 85 times.
Step 1: 0 + 520 = 520
Step 2: 520 + 520 = 1040
Step 3: 1040 + 520 = 1560
Step 4: 1560 + 520 = 2080
Step 5: 2080 + 520 = 2600
Step 6: 2600 + 520 = 3120
Step 7: 3120 + 520 = 3640
Step 8: 3640 + 520 = 4160
Step 9: 4160 + 520 = 4680
Step 10: 4680 + 520 = 5200
Step 11: 5200 + 520 = 5720
Step 12: 5720 + 520 = 6240
Step 13: 6240 + 520 = 6760
Step 14: 6760 + 520 = 7280
Step 15: 7280 + 520 = 7800
Step 16: 7800 + 520 = 8320
Step 17: 8320 + 520 = 8840
Step 18: 8840 + 520 = 9360
Step 19: 9360 + 520 = 9880
Step 20: 9880 + 520 = 10400
Step 21: 10400 + 520 = 10920
Step 22: 10920 + 520 = 11440
Step 23: 11440 + 520 = 11960
Step 24: 11960 + 520 = 12480
Step 25: 12480 + 520 = 13000
Step 26: 13000 + 520 = 13520
Step 27: 13520 + 520 = 14040
Step 28: 14040 + 520 = 14560
Step 29: 14560 + 520 = 15080
Step 30: 15080 + 520 = 15600
Step 31: 15600 + 520 = 16120
Step 32: 16120 + 520 = 16640
Step 33: 16640 + 520 = 17160
Step 34: 17160 + 520 = 17680
Step 35: 17680 + 520 = 18200
Step 36: 18200 + 520 = 18720
Step 37: 18720 + 520 = 19240
Step 38: 19240 + 520 = 19760
Step 39: 19760 + 520 = 20280
Step 40: 20280 + 520 = 20800
Step 41: 20800 + 520 = 21320
Step 42: 21320 + 520 = 21840
Step 43: 21840 + 520 = 22360
Step 44: 22360 + 520 = 22880
Step 45: 22880 + 520 = 23400
Step 46: 23400 + 520 = 23920
Step 47: 23920 + 520 = 24440
Step 48: 24440 + 520 = 24960
Step 49: 24960 + 520 = 25480
Step 50: 25480 + 520 = 26000
Step 51: 26000 + 520 = 26520
Step 52: 26520 + 520 = 27040
Step 53: 27040 + 520 = 27560
Step 54: 27560 + 520 = 28080
Step 55: 28080 + 520 = 28600
Step 56: 28600 + 520 = 29120
Step 57: 29120 + 520 = 29640
Step 58: 29640 + 520 = 30160
Step 59: 30160 + 520 = 30680
Step 60: 30680 + 520 = 31200
Step 61: 31200 + 520 = 31720
Step 62: 31720 + 520 = 32240
Step 63: 32240 + 520 = 32760
Step 64: 32760 + 520 = 33280
Step 65: 33280 + 520 = 33800
Step 66: 33800 + 520 = 34320
Step 67: 34320 + 520 = 34840
Step 68: 34840 + 520 = 35360
Step 69: 35360 + 520 = 35880
Step 70: 35880 + 520 = 36400
Step 71: 36400 + 520 = 36920
Step 72: 36920 + 520 = 37440
Step 73: 37440 + 520 = 37960
Step 74: 37960 + 520 = 38480
Step 75: 38480 + 520 = 39000
Step 76: 39000 + 520 = 39520
Step 77: 39520 + 520 = 40040
Step 78: 40040 + 520 = 40560
Step 79: 40560 + 520 = 41080
Step 80: 41080 + 520 = 41600
Step 81: 41600 + 520 = 42120
Step 82: 42120 + 520 = 42640
Step 83: 42640 + 520 = 43160
Step 84: 43160 + 520 = 43680
Step 85: 43680 + 520 = 44200

So, 520*85 = 44200