Let's roll up our sleeves and solve this. We have 668 and we're going to multiply it by 47, essentially adding 668 to itself 47 times.
Step 1: 0 + 668 = 668
Step 2: 668 + 668 = 1336
Step 3: 1336 + 668 = 2004
Step 4: 2004 + 668 = 2672
Step 5: 2672 + 668 = 3340
Step 6: 3340 + 668 = 4008
Step 7: 4008 + 668 = 4676
Step 8: 4676 + 668 = 5344
Step 9: 5344 + 668 = 6012
Step 10: 6012 + 668 = 6680
Step 11: 6680 + 668 = 7348
Step 12: 7348 + 668 = 8016
Step 13: 8016 + 668 = 8684
Step 14: 8684 + 668 = 9352
Step 15: 9352 + 668 = 10020
Step 16: 10020 + 668 = 10688
Step 17: 10688 + 668 = 11356
Step 18: 11356 + 668 = 12024
Step 19: 12024 + 668 = 12692
Step 20: 12692 + 668 = 13360
Step 21: 13360 + 668 = 14028
Step 22: 14028 + 668 = 14696
Step 23: 14696 + 668 = 15364
Step 24: 15364 + 668 = 16032
Step 25: 16032 + 668 = 16700
Step 26: 16700 + 668 = 17368
Step 27: 17368 + 668 = 18036
Step 28: 18036 + 668 = 18704
Step 29: 18704 + 668 = 19372
Step 30: 19372 + 668 = 20040
Step 31: 20040 + 668 = 20708
Step 32: 20708 + 668 = 21376
Step 33: 21376 + 668 = 22044
Step 34: 22044 + 668 = 22712
Step 35: 22712 + 668 = 23380
Step 36: 23380 + 668 = 24048
Step 37: 24048 + 668 = 24716
Step 38: 24716 + 668 = 25384
Step 39: 25384 + 668 = 26052
Step 40: 26052 + 668 = 26720
Step 41: 26720 + 668 = 27388
Step 42: 27388 + 668 = 28056
Step 43: 28056 + 668 = 28724
Step 44: 28724 + 668 = 29392
Step 45: 29392 + 668 = 30060
Step 46: 30060 + 668 = 30728
Step 47: 30728 + 668 = 31396

So, 668*47 = 31396