Example 1

Evaluate the following:

**1.** 111100_{two} + 10111_{two} + 10011_{two}

**2.** 110.011_{two} + 10.111_{two }+ 1.01_{twoÂ }

**3.** 1304_{7} + 46_{7 }+ 1304_{7Â }

**4.** 5D6C_{16} + 6ABF_{16} + 3D2_{16}

**Solution** **(1)**

**Explanation**

1st Column (from right to left) = 0 + 1 + 1 = 2. How many twos are there in 2? The answer is 1 remainder 0. Write 0 and carry 1 to column 2.

2nd Column = 1 + 0 + 1 + 1 = 3. How many twos are there in 3? The answer is 1 remainder 1. Write 1 and carry 1 to column 3.

3rd Column = 1 + 1 + 1 + 0 = 3. How many twos are there in 3? The answer is 1 remainder 1. Write 1 and carry 1 to column 4.

4th Column = 1 + 1 + 0 + 0 = 2. How many twos are there in 2? The answer is 1 remainder 0. Write 0 and carry 1 to column 5.

5th Column = 1 + 1 + 1 + 1 = 4. How many twos are there in 4? The answer is 2 remainder 0. Write 0 and carry 2 to column 6.

6th Column = 2 + 1 = 3. How many twos are there in 3? The answer is 1 remainder 1. Write 1 and carry 1 to the next column.

This yields 1100110_{two}

**Solution (2)**

**Explanation**

1st Column (from right to left) = 0 + 1 + 1 = 2. How many twos are there in 2? The answer is 1 remainder 0. Write 0 and carry 1 to column 2.

2nd Column = 1 + 1 + 1 + 1 = 4. How many twos are there in 4? The answer is 2 remainder 0. Write 0 and carry 2 to column 3.

3rd Column = 2 + 0 + 1 + 0 = 3. How many twos are there in 3? The answer is 1 remainder 1. Write 1 and carry 1 to column 4.

4th Column = 1 + 0 + 0 + 1 = 2. How many twos are there in 2? The answer is 1 remainder 0. Write 0 and carry 1 to column 5.

5th Column = 1 + 1 + 1 = 3. How many twos are there in 3? The answer is 1 remainder 1. Write 0 and carry 1 to column 6.

6th Column = 1 + 1 = 2. How many twos are there in 2? The answer is 1 remainder 0. Write 0 and carry 1 to column 7.

This yields 1010.110_{two}

**Solution (3)**

**Explanation**

1st Column (from right to left) = 4 + 6 + 6 = 16. How many sevens are there in 16? The answer is 2 remainder 2. Write 2 and carry 2 to column 2.

2nd Column = 2 + 0 + 4 + 2 = 8. How many sevens are there in 8? The answer is 1 remainder 1. Write 1 and carry 1 to column 3.

3rd Column = 1 + 3 + 4 = 8. How many sevens are there in 8? The answer is 1 remainder 1. Write 1 and carry 1 to column 4.

4th Column = 1 + 1 + 1 = 3. How many sevens are there in 3? The answer is 3 is not up to 7. Finally, Write 3.

This yields 3112_{7 }

**Solution (4)****| Hex Addition**

**Explanation**

Hex addition follows the same rules as decimal addition with the only difference being the added numerals A, B, C, D, E, and F. It may be convenient to have the decimal equivalent values of A through F handy when performing hex operations if the values have not yet been committed to memory. Below is an example of hex addition. Work through the example, and refer to the text below it for further details.

Remember A = 10, B = 11, C= 12, D = 13, E = 14, F = 15

1st Column (from right to left) = C + F + 2 = 13 + 15 + 2 = 29. How many sixteens are there in 29? The answer is 1 remainder 13. But D = 13, so write D and carry 1 to column 2.

2nd Column = 1 + 6 + B + D = 1 + 6 + 11 + 13 = 31. How many sixteens are there in 31? The answer is 1 remainder 15. But F = 15, so write F and carry 1 to column 3.

3rd Column = 1 + D + A + 3 = 1 + 13 + 10 + 3 = 27. How many sixteens are there in 27? The answer is 1 remainder 11. But B = 11, so write B and carry 1 to column 4.

4th Column = 1 + 5 + 6 = 12. 12 is not up to 16. So write 12 in this column which is also C.

This yields CBFD_{16}