OK, let's crack this. We're given 155 and our task is to multiply it by 7. Essentially, we'll be adding 155 to itself 7 times.
Step 1: 0 + 155 = 155
Step 2: 155 + 155 = 310
Step 3: 310 + 155 = 465
Step 4: 465 + 155 = 620
Step 5: 620 + 155 = 775
Step 6: 775 + 155 = 930
Step 7: 930 + 155 = 1085

So, 155*7 = 1085