Sure thing, let's get straight to it. We start with 835 and we're going to multiply it by 40, which means adding 835 to itself 40 times.
Step 1: 0 + 835 = 835
Step 2: 835 + 835 = 1670
Step 3: 1670 + 835 = 2505
Step 4: 2505 + 835 = 3340
Step 5: 3340 + 835 = 4175
Step 6: 4175 + 835 = 5010
Step 7: 5010 + 835 = 5845
Step 8: 5845 + 835 = 6680
Step 9: 6680 + 835 = 7515
Step 10: 7515 + 835 = 8350
Step 11: 8350 + 835 = 9185
Step 12: 9185 + 835 = 10020
Step 13: 10020 + 835 = 10855
Step 14: 10855 + 835 = 11690
Step 15: 11690 + 835 = 12525
Step 16: 12525 + 835 = 13360
Step 17: 13360 + 835 = 14195
Step 18: 14195 + 835 = 15030
Step 19: 15030 + 835 = 15865
Step 20: 15865 + 835 = 16700
Step 21: 16700 + 835 = 17535
Step 22: 17535 + 835 = 18370
Step 23: 18370 + 835 = 19205
Step 24: 19205 + 835 = 20040
Step 25: 20040 + 835 = 20875
Step 26: 20875 + 835 = 21710
Step 27: 21710 + 835 = 22545
Step 28: 22545 + 835 = 23380
Step 29: 23380 + 835 = 24215
Step 30: 24215 + 835 = 25050
Step 31: 25050 + 835 = 25885
Step 32: 25885 + 835 = 26720
Step 33: 26720 + 835 = 27555
Step 34: 27555 + 835 = 28390
Step 35: 28390 + 835 = 29225
Step 36: 29225 + 835 = 30060
Step 37: 30060 + 835 = 30895
Step 38: 30895 + 835 = 31730
Step 39: 31730 + 835 = 32565
Step 40: 32565 + 835 = 33400

So, 835*40 = 33400