Without delay, let's solve this. We've got 157 and we will be multiplying it by 15, that is, adding 157 to itself 15 times.
Step 1: 0 + 157 = 157
Step 2: 157 + 157 = 314
Step 3: 314 + 157 = 471
Step 4: 471 + 157 = 628
Step 5: 628 + 157 = 785
Step 6: 785 + 157 = 942
Step 7: 942 + 157 = 1099
Step 8: 1099 + 157 = 1256
Step 9: 1256 + 157 = 1413
Step 10: 1413 + 157 = 1570
Step 11: 1570 + 157 = 1727
Step 12: 1727 + 157 = 1884
Step 13: 1884 + 157 = 2041
Step 14: 2041 + 157 = 2198
Step 15: 2198 + 157 = 2355

So, 157*15 = 2355