Ours is not to reason why Ours is to Invert and Multiply… Numbering Systems Ours is not to reason why Ours is to Invert and Multiply…

Numbering Systems Since early times mankind has used many different types of symbols to represent numbers In North America we use the Base 10 system. There are several different types of number systems. Each is used for different purposes and each is different, yet similar. Binary (used in computers) Base 2 Hexadecimal(used in computers) Base 16 Decimal (used in North America) Base 10

Decimal (Base 10) It consists of 10 digits (hence the name decimal). The digits, from smallest to largest are: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. Now, any number can be broken down into columns. From right to left, the first column is the 1's column, then the 10's column, then the 100's, then the 1000's, etc.. 0 X 1000 = 0 (0 thousands) 1 X 100 = 100 (1 hundreds) 3 X 10 = 30 (3 tens) 7 X 1 = 7 (7 ones) 0+100 + 30 + 7 = 137

An Example lets try the number 77: 0 X 1000 = 0 (0 thousands) 0 X 100 = 0 (0 hundreds) 7 X 10 = 70 (7 tens) 7 X 1 = 7 (7 ones) 0+0+70 + 7 = 77

Binary (Base 2) Your computer works using the binary numbering system. The binary numbering system is ideal for representing these two states because it consists of only two digits. Once again, any number can be broken down into columns. Using the binary numbering system, from right to left, the first column is the 1's column,the 2's column, the 4's, the 8's, the 16's column, the 32's column, etc..

Let's look at the number 137 again 1 X 128 = 128 (1 one hundred twenty-eights) 0 X 64 = 0 (0 sixty-fours) 0 X 32 = 0 (0 thirty-twos) 0 X 16 =0 (0 sixteen's) 1 X 8 = 8 (1 eights) 0 X 4 = 0 (0 fours) 0 X 2 = 0 (0 twos) 1 X 1 = 1 (1 ones) 128 64 32 16 8 4 2 1

Converting Decimal to Binary There are a number of ways to convert between decimal and binary. Lets start with converting the decimal value 254 to binary. Method 1: Use the binary calculator. What we have been doing before. 20 21 22 23 24 25 Method 2: Divide the number by 2. Then divide what's left by 2, and so on until there is nothing left (0). Write down the remainder (which is either 0 or 1) at each division stage. Once there are no more divisions, list the remainder values in reverse order. This is the binary equivalent.

254 / 2 giving 127 with a remainder of 0 Reading in reverse order(Bottom to top) 1111110 Tada.. Not too shabby!

Another example, 132 decimal 132 / 2 giving 66 with a remainder of 0 66 / 2 giving 33 with a remainder of 0 33 / 2 giving 16 with a remainder of 1 16 / 2 giving 8 with a remainder of 0 8 / 2 giving 4 with a remainder of 0 4 / 2 giving 2 with a remainder of 0 2 / 2 giving 1 with a remainder of 0 1 / 2 giving 0 with a remainder of 1 Thus the binary equivalent is 10000100

128 + 0 + 0 + 0 + 8 + 0 + 0 + 1 = 137 Thus, the binary number 10001001 is equal to 137 decimal. A single digit (0 or 1) is called a 'bit' (binary digit). The table above contains 8 bits. Each column can contain either a 1 or a 0 ( 'cause there is only 2 digits in the binary numbering system). So, as you can see, it takes 8 bits to represent the decimal number 137. lets try the number 77: 128 64 32 16 8 4 2 1

0 X 128 = 0 (0 one hundred twenty-eights) 1 X 64 = 64 (1 sixty-fours) 0 X 32 = 0 (0 thirty-twos) 0 X 16 =0 (0 sixteen's) 1 X 8 = 8 (1 eights) 1 X 4 = 4 (1 fours) 0 X 2 = 0 (0 twos) 1 X 1 = 1 (1 ones) 0 + 64 + 0 + 0 + 8 + 4 + 0 + 1 = 77 Thus, the binary number 01001101 is equal to 77 decimal

Solve the first two rows using a binary calculator Then solve the last 2 rows using division. 254 8 127 13 255 1020 397 9999 20 5 16 99 178 33 207 3578

Hexadecimal Number System [Base-16] The hexadecimal number system uses SIXTEEN values to represent numbers. The values are 0 1 2 3 4 5 6 7 8 9 A B C D E F With 0 having the least value and F having the greatest value. Hexadecimal is often used to represent values [numbers and memory addresses] in computer systems.

Converting hexadecimal to decimal Convert 176 in hexadecimal to decimal Each column represents a power of 16,   176 = ---- 6 * 160 = 6 ----- 7 * 161 = 112 ------ 1 * 162 = 256 ------ = 374 Convert 11 in hexadecimal to base 10 11 = 1 * 160 = 1 * 161 = 16 + 1 = 17

Practice Hex to Decimal 3DA D9E F3A1 09 6612 55 44A9 645 3D 14DE F309 B8A4

Converting binary to hexadecimal Convert 10110 to hexadecimal. Each hexadecimal digit represents 4 binary bits. Split the binary number into groups of 4 bits, starting from the right. 1 0110 = 1 = 6 = 16 in hexadecimal. Try 1111110 base 2 to base 16 What did you get ??

Practice Bin to Hex 1010101 1000100 0010010 0101101 11110111 101010101 11111110 1110001 11011100 1011100 1000 1110

Converting decimal to hexadecimal Convert 232 decimal to hexadecimal. Use the same method used earlier to divide decimal to binary, but divide by 16 this time. 232 / 16 = 14 with a remainder of 8 8 / 16 = you can’t have since 8 is smaller than 16. So the 8 becomes the last digit. So you get 14 and a 8. Remember… (14 decimal = E)  = E816 A=10, B=11, C=12, D=13, E=14, F=15

Practice Decimal to Hex 15 15831 902 55 6612 5589 13 91145 3 14 309 84 96 11 1449 64000

Notation To avoid confusion, we often add a suffix to indicate the number of the base. 162h h means hexadecimal 16216 16 means base 16  162d d means decimal 16210 10 means base 10 162o o means octal 1628 8 means base 8  101b b means binary 1012 2 means base 2

More Converting For Review, Work on the handout called “Digital 1” Specific problems or questions come and ask me. Copy and complete the following charts in your books.

Binary Hex Decimal 101010102 001100112 111111112 101110102 111100102 001000112 000100012 100000002 100101012

Hex Binary Decimal 345 AF56 78C1 B0D5 7156 9 185 FFFF FFF FF

Decimal Hex Binary 345 32768 255 1289 15 1000 1024 999 1678 2000