OK, let's work through this together. We're starting with 331 and we're going to multiply it by 16, which means we add 331 to itself 16 times.
Step 1: 0 + 331 = 331
Step 2: 331 + 331 = 662
Step 3: 662 + 331 = 993
Step 4: 993 + 331 = 1324
Step 5: 1324 + 331 = 1655
Step 6: 1655 + 331 = 1986
Step 7: 1986 + 331 = 2317
Step 8: 2317 + 331 = 2648
Step 9: 2648 + 331 = 2979
Step 10: 2979 + 331 = 3310
Step 11: 3310 + 331 = 3641
Step 12: 3641 + 331 = 3972
Step 13: 3972 + 331 = 4303
Step 14: 4303 + 331 = 4634
Step 15: 4634 + 331 = 4965
Step 16: 4965 + 331 = 5296

So, 331*16 = 5296