Let's roll up our sleeves and solve this. We have 397 and we're going to multiply it by 10, essentially adding 397 to itself 10 times.
Step 1: 0 + 397 = 397
Step 2: 397 + 397 = 794
Step 3: 794 + 397 = 1191
Step 4: 1191 + 397 = 1588
Step 5: 1588 + 397 = 1985
Step 6: 1985 + 397 = 2382
Step 7: 2382 + 397 = 2779
Step 8: 2779 + 397 = 3176
Step 9: 3176 + 397 = 3573
Step 10: 3573 + 397 = 3970

So, 397*10 = 3970