Let's get this math done. We have 400 and we're going to multiply it by 46. This is the same as taking 400 and adding it to itself 46 times.
Step 1: 0 + 400 = 400
Step 2: 400 + 400 = 800
Step 3: 800 + 400 = 1200
Step 4: 1200 + 400 = 1600
Step 5: 1600 + 400 = 2000
Step 6: 2000 + 400 = 2400
Step 7: 2400 + 400 = 2800
Step 8: 2800 + 400 = 3200
Step 9: 3200 + 400 = 3600
Step 10: 3600 + 400 = 4000
Step 11: 4000 + 400 = 4400
Step 12: 4400 + 400 = 4800
Step 13: 4800 + 400 = 5200
Step 14: 5200 + 400 = 5600
Step 15: 5600 + 400 = 6000
Step 16: 6000 + 400 = 6400
Step 17: 6400 + 400 = 6800
Step 18: 6800 + 400 = 7200
Step 19: 7200 + 400 = 7600
Step 20: 7600 + 400 = 8000
Step 21: 8000 + 400 = 8400
Step 22: 8400 + 400 = 8800
Step 23: 8800 + 400 = 9200
Step 24: 9200 + 400 = 9600
Step 25: 9600 + 400 = 10000
Step 26: 10000 + 400 = 10400
Step 27: 10400 + 400 = 10800
Step 28: 10800 + 400 = 11200
Step 29: 11200 + 400 = 11600
Step 30: 11600 + 400 = 12000
Step 31: 12000 + 400 = 12400
Step 32: 12400 + 400 = 12800
Step 33: 12800 + 400 = 13200
Step 34: 13200 + 400 = 13600
Step 35: 13600 + 400 = 14000
Step 36: 14000 + 400 = 14400
Step 37: 14400 + 400 = 14800
Step 38: 14800 + 400 = 15200
Step 39: 15200 + 400 = 15600
Step 40: 15600 + 400 = 16000
Step 41: 16000 + 400 = 16400
Step 42: 16400 + 400 = 16800
Step 43: 16800 + 400 = 17200
Step 44: 17200 + 400 = 17600
Step 45: 17600 + 400 = 18000
Step 46: 18000 + 400 = 18400

So, 400*46 = 18400