OK, let's work through this together. We're starting with 309 and we're going to multiply it by 19, which means we add 309 to itself 19 times.
Step 1: 0 + 309 = 309
Step 2: 309 + 309 = 618
Step 3: 618 + 309 = 927
Step 4: 927 + 309 = 1236
Step 5: 1236 + 309 = 1545
Step 6: 1545 + 309 = 1854
Step 7: 1854 + 309 = 2163
Step 8: 2163 + 309 = 2472
Step 9: 2472 + 309 = 2781
Step 10: 2781 + 309 = 3090
Step 11: 3090 + 309 = 3399
Step 12: 3399 + 309 = 3708
Step 13: 3708 + 309 = 4017
Step 14: 4017 + 309 = 4326
Step 15: 4326 + 309 = 4635
Step 16: 4635 + 309 = 4944
Step 17: 4944 + 309 = 5253
Step 18: 5253 + 309 = 5562
Step 19: 5562 + 309 = 5871

So, 309*19 = 5871