Sure thing! We've got 664 and we're gonna multiply it by 7. That's the same as adding 664 to itself 7 times.
Step 1: 0 + 664 = 664
Step 2: 664 + 664 = 1328
Step 3: 1328 + 664 = 1992
Step 4: 1992 + 664 = 2656
Step 5: 2656 + 664 = 3320
Step 6: 3320 + 664 = 3984
Step 7: 3984 + 664 = 4648

So, 664*7 = 4648