Alright, let's solve this math problem step by step. First, we have the number 156. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 15. So, we're going to take the number 156 and add it to itself 15 times.
Step 1: 0 + 156 = 156
Step 2: 156 + 156 = 312
Step 3: 312 + 156 = 468
Step 4: 468 + 156 = 624
Step 5: 624 + 156 = 780
Step 6: 780 + 156 = 936
Step 7: 936 + 156 = 1092
Step 8: 1092 + 156 = 1248
Step 9: 1248 + 156 = 1404
Step 10: 1404 + 156 = 1560
Step 11: 1560 + 156 = 1716
Step 12: 1716 + 156 = 1872
Step 13: 1872 + 156 = 2028
Step 14: 2028 + 156 = 2184
Step 15: 2184 + 156 = 2340

So, 156*15 = 2340