OK, let's work through this together. We're starting with 670 and we're going to multiply it by 7, which means we add 670 to itself 7 times.
Step 1: 0 + 670 = 670
Step 2: 670 + 670 = 1340
Step 3: 1340 + 670 = 2010
Step 4: 2010 + 670 = 2680
Step 5: 2680 + 670 = 3350
Step 6: 3350 + 670 = 4020
Step 7: 4020 + 670 = 4690

So, 670*7 = 4690