Without delay, let's solve this. We've got 687 and we will be multiplying it by 28, that is, adding 687 to itself 28 times.
Step 1: 0 + 687 = 687
Step 2: 687 + 687 = 1374
Step 3: 1374 + 687 = 2061
Step 4: 2061 + 687 = 2748
Step 5: 2748 + 687 = 3435
Step 6: 3435 + 687 = 4122
Step 7: 4122 + 687 = 4809
Step 8: 4809 + 687 = 5496
Step 9: 5496 + 687 = 6183
Step 10: 6183 + 687 = 6870
Step 11: 6870 + 687 = 7557
Step 12: 7557 + 687 = 8244
Step 13: 8244 + 687 = 8931
Step 14: 8931 + 687 = 9618
Step 15: 9618 + 687 = 10305
Step 16: 10305 + 687 = 10992
Step 17: 10992 + 687 = 11679
Step 18: 11679 + 687 = 12366
Step 19: 12366 + 687 = 13053
Step 20: 13053 + 687 = 13740
Step 21: 13740 + 687 = 14427
Step 22: 14427 + 687 = 15114
Step 23: 15114 + 687 = 15801
Step 24: 15801 + 687 = 16488
Step 25: 16488 + 687 = 17175
Step 26: 17175 + 687 = 17862
Step 27: 17862 + 687 = 18549
Step 28: 18549 + 687 = 19236

So, 687*28 = 19236