OK, let's work through this together. We're starting with 857 and we're going to multiply it by 70, which means we add 857 to itself 70 times.
Step 1: 0 + 857 = 857
Step 2: 857 + 857 = 1714
Step 3: 1714 + 857 = 2571
Step 4: 2571 + 857 = 3428
Step 5: 3428 + 857 = 4285
Step 6: 4285 + 857 = 5142
Step 7: 5142 + 857 = 5999
Step 8: 5999 + 857 = 6856
Step 9: 6856 + 857 = 7713
Step 10: 7713 + 857 = 8570
Step 11: 8570 + 857 = 9427
Step 12: 9427 + 857 = 10284
Step 13: 10284 + 857 = 11141
Step 14: 11141 + 857 = 11998
Step 15: 11998 + 857 = 12855
Step 16: 12855 + 857 = 13712
Step 17: 13712 + 857 = 14569
Step 18: 14569 + 857 = 15426
Step 19: 15426 + 857 = 16283
Step 20: 16283 + 857 = 17140
Step 21: 17140 + 857 = 17997
Step 22: 17997 + 857 = 18854
Step 23: 18854 + 857 = 19711
Step 24: 19711 + 857 = 20568
Step 25: 20568 + 857 = 21425
Step 26: 21425 + 857 = 22282
Step 27: 22282 + 857 = 23139
Step 28: 23139 + 857 = 23996
Step 29: 23996 + 857 = 24853
Step 30: 24853 + 857 = 25710
Step 31: 25710 + 857 = 26567
Step 32: 26567 + 857 = 27424
Step 33: 27424 + 857 = 28281
Step 34: 28281 + 857 = 29138
Step 35: 29138 + 857 = 29995
Step 36: 29995 + 857 = 30852
Step 37: 30852 + 857 = 31709
Step 38: 31709 + 857 = 32566
Step 39: 32566 + 857 = 33423
Step 40: 33423 + 857 = 34280
Step 41: 34280 + 857 = 35137
Step 42: 35137 + 857 = 35994
Step 43: 35994 + 857 = 36851
Step 44: 36851 + 857 = 37708
Step 45: 37708 + 857 = 38565
Step 46: 38565 + 857 = 39422
Step 47: 39422 + 857 = 40279
Step 48: 40279 + 857 = 41136
Step 49: 41136 + 857 = 41993
Step 50: 41993 + 857 = 42850
Step 51: 42850 + 857 = 43707
Step 52: 43707 + 857 = 44564
Step 53: 44564 + 857 = 45421
Step 54: 45421 + 857 = 46278
Step 55: 46278 + 857 = 47135
Step 56: 47135 + 857 = 47992
Step 57: 47992 + 857 = 48849
Step 58: 48849 + 857 = 49706
Step 59: 49706 + 857 = 50563
Step 60: 50563 + 857 = 51420
Step 61: 51420 + 857 = 52277
Step 62: 52277 + 857 = 53134
Step 63: 53134 + 857 = 53991
Step 64: 53991 + 857 = 54848
Step 65: 54848 + 857 = 55705
Step 66: 55705 + 857 = 56562
Step 67: 56562 + 857 = 57419
Step 68: 57419 + 857 = 58276
Step 69: 58276 + 857 = 59133
Step 70: 59133 + 857 = 59990

So, 857*70 = 59990