Let's roll up our sleeves and solve this. We have 456 and we're going to multiply it by 16, essentially adding 456 to itself 16 times.
Step 1: 0 + 456 = 456
Step 2: 456 + 456 = 912
Step 3: 912 + 456 = 1368
Step 4: 1368 + 456 = 1824
Step 5: 1824 + 456 = 2280
Step 6: 2280 + 456 = 2736
Step 7: 2736 + 456 = 3192
Step 8: 3192 + 456 = 3648
Step 9: 3648 + 456 = 4104
Step 10: 4104 + 456 = 4560
Step 11: 4560 + 456 = 5016
Step 12: 5016 + 456 = 5472
Step 13: 5472 + 456 = 5928
Step 14: 5928 + 456 = 6384
Step 15: 6384 + 456 = 6840
Step 16: 6840 + 456 = 7296

So, 456*16 = 7296