Alright, let's solve this math problem step by step. First, we have the number 287. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 20. So, we're going to take the number 287 and add it to itself 20 times.
Step 1: 0 + 287 = 287
Step 2: 287 + 287 = 574
Step 3: 574 + 287 = 861
Step 4: 861 + 287 = 1148
Step 5: 1148 + 287 = 1435
Step 6: 1435 + 287 = 1722
Step 7: 1722 + 287 = 2009
Step 8: 2009 + 287 = 2296
Step 9: 2296 + 287 = 2583
Step 10: 2583 + 287 = 2870
Step 11: 2870 + 287 = 3157
Step 12: 3157 + 287 = 3444
Step 13: 3444 + 287 = 3731
Step 14: 3731 + 287 = 4018
Step 15: 4018 + 287 = 4305
Step 16: 4305 + 287 = 4592
Step 17: 4592 + 287 = 4879
Step 18: 4879 + 287 = 5166
Step 19: 5166 + 287 = 5453
Step 20: 5453 + 287 = 5740

So, 287*20 = 5740