Let's roll up our sleeves and solve this. We have 607 and we're going to multiply it by 7, essentially adding 607 to itself 7 times.
Step 1: 0 + 607 = 607
Step 2: 607 + 607 = 1214
Step 3: 1214 + 607 = 1821
Step 4: 1821 + 607 = 2428
Step 5: 2428 + 607 = 3035
Step 6: 3035 + 607 = 3642
Step 7: 3642 + 607 = 4249

So, 607*7 = 4249