OK, let's work through this together. We're starting with 154 and we're going to multiply it by 40, which means we add 154 to itself 40 times.
Step 1: 0 + 154 = 154
Step 2: 154 + 154 = 308
Step 3: 308 + 154 = 462
Step 4: 462 + 154 = 616
Step 5: 616 + 154 = 770
Step 6: 770 + 154 = 924
Step 7: 924 + 154 = 1078
Step 8: 1078 + 154 = 1232
Step 9: 1232 + 154 = 1386
Step 10: 1386 + 154 = 1540
Step 11: 1540 + 154 = 1694
Step 12: 1694 + 154 = 1848
Step 13: 1848 + 154 = 2002
Step 14: 2002 + 154 = 2156
Step 15: 2156 + 154 = 2310
Step 16: 2310 + 154 = 2464
Step 17: 2464 + 154 = 2618
Step 18: 2618 + 154 = 2772
Step 19: 2772 + 154 = 2926
Step 20: 2926 + 154 = 3080
Step 21: 3080 + 154 = 3234
Step 22: 3234 + 154 = 3388
Step 23: 3388 + 154 = 3542
Step 24: 3542 + 154 = 3696
Step 25: 3696 + 154 = 3850
Step 26: 3850 + 154 = 4004
Step 27: 4004 + 154 = 4158
Step 28: 4158 + 154 = 4312
Step 29: 4312 + 154 = 4466
Step 30: 4466 + 154 = 4620
Step 31: 4620 + 154 = 4774
Step 32: 4774 + 154 = 4928
Step 33: 4928 + 154 = 5082
Step 34: 5082 + 154 = 5236
Step 35: 5236 + 154 = 5390
Step 36: 5390 + 154 = 5544
Step 37: 5544 + 154 = 5698
Step 38: 5698 + 154 = 5852
Step 39: 5852 + 154 = 6006
Step 40: 6006 + 154 = 6160

So, 154*40 = 6160