Let's get this math done. We have 961 and we're going to multiply it by 31. This is the same as taking 961 and adding it to itself 31 times.
Step 1: 0 + 961 = 961
Step 2: 961 + 961 = 1922
Step 3: 1922 + 961 = 2883
Step 4: 2883 + 961 = 3844
Step 5: 3844 + 961 = 4805
Step 6: 4805 + 961 = 5766
Step 7: 5766 + 961 = 6727
Step 8: 6727 + 961 = 7688
Step 9: 7688 + 961 = 8649
Step 10: 8649 + 961 = 9610
Step 11: 9610 + 961 = 10571
Step 12: 10571 + 961 = 11532
Step 13: 11532 + 961 = 12493
Step 14: 12493 + 961 = 13454
Step 15: 13454 + 961 = 14415
Step 16: 14415 + 961 = 15376
Step 17: 15376 + 961 = 16337
Step 18: 16337 + 961 = 17298
Step 19: 17298 + 961 = 18259
Step 20: 18259 + 961 = 19220
Step 21: 19220 + 961 = 20181
Step 22: 20181 + 961 = 21142
Step 23: 21142 + 961 = 22103
Step 24: 22103 + 961 = 23064
Step 25: 23064 + 961 = 24025
Step 26: 24025 + 961 = 24986
Step 27: 24986 + 961 = 25947
Step 28: 25947 + 961 = 26908
Step 29: 26908 + 961 = 27869
Step 30: 27869 + 961 = 28830
Step 31: 28830 + 961 = 29791

So, 961*31 = 29791