Without delay, let's solve this. We've got 810 and we will be multiplying it by 35, that is, adding 810 to itself 35 times.
Step 1: 0 + 810 = 810
Step 2: 810 + 810 = 1620
Step 3: 1620 + 810 = 2430
Step 4: 2430 + 810 = 3240
Step 5: 3240 + 810 = 4050
Step 6: 4050 + 810 = 4860
Step 7: 4860 + 810 = 5670
Step 8: 5670 + 810 = 6480
Step 9: 6480 + 810 = 7290
Step 10: 7290 + 810 = 8100
Step 11: 8100 + 810 = 8910
Step 12: 8910 + 810 = 9720
Step 13: 9720 + 810 = 10530
Step 14: 10530 + 810 = 11340
Step 15: 11340 + 810 = 12150
Step 16: 12150 + 810 = 12960
Step 17: 12960 + 810 = 13770
Step 18: 13770 + 810 = 14580
Step 19: 14580 + 810 = 15390
Step 20: 15390 + 810 = 16200
Step 21: 16200 + 810 = 17010
Step 22: 17010 + 810 = 17820
Step 23: 17820 + 810 = 18630
Step 24: 18630 + 810 = 19440
Step 25: 19440 + 810 = 20250
Step 26: 20250 + 810 = 21060
Step 27: 21060 + 810 = 21870
Step 28: 21870 + 810 = 22680
Step 29: 22680 + 810 = 23490
Step 30: 23490 + 810 = 24300
Step 31: 24300 + 810 = 25110
Step 32: 25110 + 810 = 25920
Step 33: 25920 + 810 = 26730
Step 34: 26730 + 810 = 27540
Step 35: 27540 + 810 = 28350

So, 810*35 = 28350