Let's roll up our sleeves and solve this. We have 39 and we're going to multiply it by 11, essentially adding 39 to itself 11 times.
Step 1: 0 + 39 = 39
Step 2: 39 + 39 = 78
Step 3: 78 + 39 = 117
Step 4: 117 + 39 = 156
Step 5: 156 + 39 = 195
Step 6: 195 + 39 = 234
Step 7: 234 + 39 = 273
Step 8: 273 + 39 = 312
Step 9: 312 + 39 = 351
Step 10: 351 + 39 = 390
Step 11: 390 + 39 = 429

So, 39*11 = 429