OK, let's work through this together. We're starting with 143 and we're going to multiply it by 6, which means we add 143 to itself 6 times.
Step 1: 0 + 143 = 143
Step 2: 143 + 143 = 286
Step 3: 286 + 143 = 429
Step 4: 429 + 143 = 572
Step 5: 572 + 143 = 715
Step 6: 715 + 143 = 858

So, 143*6 = 858