Let's get this math done. We have 158 and we're going to multiply it by 10. This is the same as taking 158 and adding it to itself 10 times.
Step 1: 0 + 158 = 158
Step 2: 158 + 158 = 316
Step 3: 316 + 158 = 474
Step 4: 474 + 158 = 632
Step 5: 632 + 158 = 790
Step 6: 790 + 158 = 948
Step 7: 948 + 158 = 1106
Step 8: 1106 + 158 = 1264
Step 9: 1264 + 158 = 1422
Step 10: 1422 + 158 = 1580

So, 158*10 = 1580