OK, let's work through this together. We're starting with 261 and we're going to multiply it by 13, which means we add 261 to itself 13 times.
Step 1: 0 + 261 = 261
Step 2: 261 + 261 = 522
Step 3: 522 + 261 = 783
Step 4: 783 + 261 = 1044
Step 5: 1044 + 261 = 1305
Step 6: 1305 + 261 = 1566
Step 7: 1566 + 261 = 1827
Step 8: 1827 + 261 = 2088
Step 9: 2088 + 261 = 2349
Step 10: 2349 + 261 = 2610
Step 11: 2610 + 261 = 2871
Step 12: 2871 + 261 = 3132
Step 13: 3132 + 261 = 3393

So, 261*13 = 3393