Sure thing! We've got 81 and we're gonna multiply it by 35. That's the same as adding 81 to itself 35 times.
Step 1: 0 + 81 = 81
Step 2: 81 + 81 = 162
Step 3: 162 + 81 = 243
Step 4: 243 + 81 = 324
Step 5: 324 + 81 = 405
Step 6: 405 + 81 = 486
Step 7: 486 + 81 = 567
Step 8: 567 + 81 = 648
Step 9: 648 + 81 = 729
Step 10: 729 + 81 = 810
Step 11: 810 + 81 = 891
Step 12: 891 + 81 = 972
Step 13: 972 + 81 = 1053
Step 14: 1053 + 81 = 1134
Step 15: 1134 + 81 = 1215
Step 16: 1215 + 81 = 1296
Step 17: 1296 + 81 = 1377
Step 18: 1377 + 81 = 1458
Step 19: 1458 + 81 = 1539
Step 20: 1539 + 81 = 1620
Step 21: 1620 + 81 = 1701
Step 22: 1701 + 81 = 1782
Step 23: 1782 + 81 = 1863
Step 24: 1863 + 81 = 1944
Step 25: 1944 + 81 = 2025
Step 26: 2025 + 81 = 2106
Step 27: 2106 + 81 = 2187
Step 28: 2187 + 81 = 2268
Step 29: 2268 + 81 = 2349
Step 30: 2349 + 81 = 2430
Step 31: 2430 + 81 = 2511
Step 32: 2511 + 81 = 2592
Step 33: 2592 + 81 = 2673
Step 34: 2673 + 81 = 2754
Step 35: 2754 + 81 = 2835

So, 81*35 = 2835