Sure thing, let's get straight to it. We start with 672 and we're going to multiply it by 5, which means adding 672 to itself 5 times.
Step 1: 0 + 672 = 672
Step 2: 672 + 672 = 1344
Step 3: 1344 + 672 = 2016
Step 4: 2016 + 672 = 2688
Step 5: 2688 + 672 = 3360

So, 672*5 = 3360