1. CCNA Math Practice-Binary Octets Practice your CCNA Math by using these slides as flash cards -Binary edition-

2. Common Binary to Decimal Conversions 00000001 1 * 2^0= ? This looks a bit odd… The Answer is: 1

3. Common Binary to Decimal Conversions 00000010 1 * 2^1= ? As small as even can be… The Answer is: 2

4. Common Binary to Decimal Conversions 00000100 1 * 2^2= ? Two squared is… The Answer is: 4

5. Common Binary to Decimal Conversions 00001000 1 * 2^3= ? The next step up would be 16… The Answer is: 8

6. Common Binary to Decimal Conversions 00010000 1 * 2^4= ? 256 / 16 = ? Four Squared The Answer is: 16

7. Common Binary to Decimal Conversions 00100000 1 * 2^5= ? 2 * 16 = ? Third largest bit value for a byte The Answer is: 32

8. Common Binary to Decimal Conversions 01000000 1 * 2^6= ? 256 / 4 = ? Second largest bit value for a byte The Answer is: 64

9. Common Binary to Decimal Conversions 10000000 1 * 2^7= ? 256 / 2 = ? The Answer is: 128 Class B Subnets w/9 bits: 510 Useable Subnets (Class B w/ 9 bits subnetting) and 126 hosts per subnet

10. Common Binary to Decimal Conversions 11000000 128 + 64 = ? The Answer is: 192 Class C Subnets: 2 Useable Subnets (ClassC) with 62 hosts per subnet

11. Common Binary to Decimal Conversions 11100000 256 - 32 = ? The Answer is: 224 Class C Subnets: 6 Useable Subnets (ClassC) with 30 hosts per subnet

12. Common Binary to Decimal Conversions 11110000 256 - 16 = ? The Answer is: 240 Class C Subnets: 14 Useable Subnets (ClassC) with 14 hosts per subnet

13. Common Binary to Decimal Conversions 11111000 2^5 Subnets created... 240 + 8 = ? The Answer is: 248 Class C Subnets: 30 Useable Subnets (ClassC) with 6 hosts per subnet

14. Common Binary to Decimal Conversions 11111100 Good Subnet Mask for Point- to-Point Links… 240 + 8 + 4 = ? The Answer is: 252 Class C Subnets: 62 Useable Subnets (ClassC) with 2 hosts per subnet

15. Common Binary to Decimal Conversions 11111110 240 + 8 + 4 + 2= ? 255 - 1 = ? The Decimal Answer is: 254 Class B Subnets: 126 Useable Subnets (ClassB) with 510 hosts per subnet

16. Common Binary to Decimal Conversions 11111111 Maximum value for a byte… Most Subnet Masks include one of these The Answer is: 255 Class B Subnets: 254 Useable Subnets (ClassB) with 254 hosts per subnet

17. Common Binary to Decimal Conversions 00000011 Only four could be more… 2 + 1 = ? The Answer is: 3 Wildcard Mask for 255.255.255.252

18. Common Binary to Decimal Conversions 00000111 Almost 2^3… 8 - 1 = ? The Answer is: 7 Wildcard Mask for 255.255.255.248

19. Common Binary to Decimal Conversions 00001111 Almost 16… 16 - 1 = ? The Answer is: 15 Wildcard Mask for 255.255.255.240

20. Common Binary to Decimal Conversions 00011111 Add all of these ones, and get one less than next 1 is worth… 32 - 1 = ? The Answer is: 31 Wildcard Mask for 255.255.255.224

21. Common Binary to Decimal Conversions 00111111 Almost 64… 64 - 1 = ? The Answer is: 63 Wildcard Mask for 255.255.255.192

22. Common Binary to Decimal Conversions 01111111 First Octet of the Loopback Address… 128 - 1 = ? The Answer is: 127 Wildcard Mask for 255.255.255.128

23. Changing to a few common Decimals Feel free to use a sheet of paper to work on the next few slides. The following are a few decimals that are frequently converted to binary.

24. Common Decimal to Binary Conversions Decimal 10 to Binary >=128? No 0… >=64? No 00… >=32 or >=16? No 0000…. >=8? Yes 00001… 10-8=2 The answer is: 00001010

25. Common Decimal to Binary Conversions Decimal 168 to Binary >=128? Yes 1… 168-128=40 >=64? No 10… >=32? Yes 101… 40-32=8 >=16? No 1010… >=8? Yes The answer is: 10101000

26. Common Decimal to Binary Conversions Decimal 172 to Binary 172>=128? Yes 1… 172-128=44 44>=64? No 10… 44>=32? Yes 101…44-32=12 12>=16? No 1010… 12>=8? Yes 10101… 12-8=4 The answer is: 10101100

27. CCNA Math Practice Nice Job! The End…for now