OK, let's crack this. We're given 27 and our task is to multiply it by 28. Essentially, we'll be adding 27 to itself 28 times.
Step 1: 0 + 27 = 27
Step 2: 27 + 27 = 54
Step 3: 54 + 27 = 81
Step 4: 81 + 27 = 108
Step 5: 108 + 27 = 135
Step 6: 135 + 27 = 162
Step 7: 162 + 27 = 189
Step 8: 189 + 27 = 216
Step 9: 216 + 27 = 243
Step 10: 243 + 27 = 270
Step 11: 270 + 27 = 297
Step 12: 297 + 27 = 324
Step 13: 324 + 27 = 351
Step 14: 351 + 27 = 378
Step 15: 378 + 27 = 405
Step 16: 405 + 27 = 432
Step 17: 432 + 27 = 459
Step 18: 459 + 27 = 486
Step 19: 486 + 27 = 513
Step 20: 513 + 27 = 540
Step 21: 540 + 27 = 567
Step 22: 567 + 27 = 594
Step 23: 594 + 27 = 621
Step 24: 621 + 27 = 648
Step 25: 648 + 27 = 675
Step 26: 675 + 27 = 702
Step 27: 702 + 27 = 729
Step 28: 729 + 27 = 756

So, 27*28 = 756