Let's roll up our sleeves and solve this. We have 270 and we're going to multiply it by 13, essentially adding 270 to itself 13 times.
Step 1: 0 + 270 = 270
Step 2: 270 + 270 = 540
Step 3: 540 + 270 = 810
Step 4: 810 + 270 = 1080
Step 5: 1080 + 270 = 1350
Step 6: 1350 + 270 = 1620
Step 7: 1620 + 270 = 1890
Step 8: 1890 + 270 = 2160
Step 9: 2160 + 270 = 2430
Step 10: 2430 + 270 = 2700
Step 11: 2700 + 270 = 2970
Step 12: 2970 + 270 = 3240
Step 13: 3240 + 270 = 3510

So, 270*13 = 3510