Let's roll up our sleeves and solve this. We have 172 and we're going to multiply it by 7, essentially adding 172 to itself 7 times.
Step 1: 0 + 172 = 172
Step 2: 172 + 172 = 344
Step 3: 344 + 172 = 516
Step 4: 516 + 172 = 688
Step 5: 688 + 172 = 860
Step 6: 860 + 172 = 1032
Step 7: 1032 + 172 = 1204

So, 172*7 = 1204