OK, let's work through this together. We're starting with 637 and we're going to multiply it by 10, which means we add 637 to itself 10 times.
Step 1: 0 + 637 = 637
Step 2: 637 + 637 = 1274
Step 3: 1274 + 637 = 1911
Step 4: 1911 + 637 = 2548
Step 5: 2548 + 637 = 3185
Step 6: 3185 + 637 = 3822
Step 7: 3822 + 637 = 4459
Step 8: 4459 + 637 = 5096
Step 9: 5096 + 637 = 5733
Step 10: 5733 + 637 = 6370

So, 637*10 = 6370