Let's roll up our sleeves and solve this. We have 808 and we're going to multiply it by 25, essentially adding 808 to itself 25 times.
Step 1: 0 + 808 = 808
Step 2: 808 + 808 = 1616
Step 3: 1616 + 808 = 2424
Step 4: 2424 + 808 = 3232
Step 5: 3232 + 808 = 4040
Step 6: 4040 + 808 = 4848
Step 7: 4848 + 808 = 5656
Step 8: 5656 + 808 = 6464
Step 9: 6464 + 808 = 7272
Step 10: 7272 + 808 = 8080
Step 11: 8080 + 808 = 8888
Step 12: 8888 + 808 = 9696
Step 13: 9696 + 808 = 10504
Step 14: 10504 + 808 = 11312
Step 15: 11312 + 808 = 12120
Step 16: 12120 + 808 = 12928
Step 17: 12928 + 808 = 13736
Step 18: 13736 + 808 = 14544
Step 19: 14544 + 808 = 15352
Step 20: 15352 + 808 = 16160
Step 21: 16160 + 808 = 16968
Step 22: 16968 + 808 = 17776
Step 23: 17776 + 808 = 18584
Step 24: 18584 + 808 = 19392
Step 25: 19392 + 808 = 20200

So, 808*25 = 20200