Let's roll up our sleeves and solve this. We have 456 and we're going to multiply it by 7, essentially adding 456 to itself 7 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

So, 456*7 = 3192