Let's roll up our sleeves and solve this. We have 159 and we're going to multiply it by 7, essentially adding 159 to itself 7 times.
Step 1: 0 + 159 = 159
Step 2: 159 + 159 = 318
Step 3: 318 + 159 = 477
Step 4: 477 + 159 = 636
Step 5: 636 + 159 = 795
Step 6: 795 + 159 = 954
Step 7: 954 + 159 = 1113

So, 159*7 = 1113