Without delay, let's solve this. We've got 721 and we will be multiplying it by 4, that is, adding 721 to itself 4 times.
Step 1: 0 + 721 = 721
Step 2: 721 + 721 = 1442
Step 3: 1442 + 721 = 2163
Step 4: 2163 + 721 = 2884

So, 721*4 = 2884