OK, let's work through this together. We're starting with 351 and we're going to multiply it by 6, which means we add 351 to itself 6 times.
Step 1: 0 + 351 = 351
Step 2: 351 + 351 = 702
Step 3: 702 + 351 = 1053
Step 4: 1053 + 351 = 1404
Step 5: 1404 + 351 = 1755
Step 6: 1755 + 351 = 2106

So, 351*6 = 2106