Slide 4-1 Copyright © 2005 Pearson Education, Inc. SEVENTH EDITION and EXPANDED SEVENTH EDITION

Copyright © 2005 Pearson Education, Inc. Chapter 4 Systems of Numeration

Copyright © 2005 Pearson Education, Inc. 4.1 Additive, Multiplicative, and Ciphered Systems of Numeration

Slide 4-4 Copyright © 2005 Pearson Education, Inc. Systems of Numeration A system of numeration consists of a set of numerals and a scheme or rule for combining the numerals to represent numbers A number is a quantity. It answers the question “how many?” A numeral is a symbol used to represent the number (amount).

Slide 4-5 Copyright © 2005 Pearson Education, Inc. Types Of Numeration Systems Four types of systems used by different cultures will be discussed. They are:  Additive (or repetitive)  Multiplicative  Ciphered  Place-value

Slide 4-6 Copyright © 2005 Pearson Education, Inc. Additive Systems An additive system is one in which the number represented by a set of numerals is simply the sum of the values of the numerals. It is one of the oldest and most primitive types of systems. Examples: Egyptian hieroglyphics and Roman numerals.

Slide 4-7 Copyright © 2005 Pearson Education, Inc. Multiplicative Systems Multiplicative systems are more similar to the Hindu-Arabic system which we use today. Example: Chinese numerals.

Slide 4-8 Copyright © 2005 Pearson Education, Inc. Ciphered Systems In this system, there are numerals for numbers up to and including the base and for multiples of the base. The numbers (amounts) represented by a specific set of numerals is the sum of the values of the numerals.

Slide 4-9 Copyright © 2005 Pearson Education, Inc. Examples of Ciphered Systems: Ionic Greek system (developed about 3000 B.C. and used letters of Greek alphabet as numerals). Hebrew system Coptic system Hindu system Early Arabic systems

Copyright © 2005 Pearson Education, Inc. 4.2 Place-Value or Positional-Value Numeration Systems

Slide 4-11 Copyright © 2005 Pearson Education, Inc. Place-Value System The value of the symbol depends on its position in the representation of the number. It is the most common type of numeration system in the world today. The most common place-value system is the Hindu-Arabic numeration system. This is used in the United States.

Slide 4-12 Copyright © 2005 Pearson Education, Inc. Place-Value System A true positional-value system requires a base and a set of symbols, including a symbol for zero and one for each counting number less than the base. The most common place-value system is the base 10 system.  It is called the decimal number system.

Slide 4-13 Copyright © 2005 Pearson Education, Inc. Hindu-Arabic System Digits: In the Hindu-Arabic system, the digits are 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. Positions: In the Hindu-Arabic system, the positional values or place values are: … 10 5, 10 4, 10 3, 10 2, 10 1, 10 0.

Slide 4-14 Copyright © 2005 Pearson Education, Inc. Expanded Form To evaluate a number in this system, begin with the rightmost digit and multiply it by 1. Multiply the second digit from the right by base 10. Continue by taking the next digit to the left and multiplying by the next power of 10. In general, we multiply the digit n places from the right by 10 n-1 in order to show expanded form.

Slide 4-15 Copyright © 2005 Pearson Education, Inc. Example: Expanded Form Write the Hindu-Arabic numeral in expanded form. a) 63 b) 3769 Solution: 63 = (6 x 10 1 ) + (3 x 1 ) or (6 x 10) = (3 x 1000) + (7 x 100) + (6 x 10) + 9 or (3 x 10 3 ) + (7 x 10 2 ) + (6 x 10 1 ) + (9 x 1 )

Copyright © 2005 Pearson Education, Inc. 4.3 Other Bases

Slide 4-17 Copyright © 2005 Pearson Education, Inc. Bases Any counting number greater than 1 may be used as a base for a positional-value numeration system. If a positional-value system has a base b, then its positional values will be … b 4, b 3, b 2, b 1, b 0. Hindu-Arabic system uses base 10.

Slide 4-18 Copyright © 2005 Pearson Education, Inc. Example: Converting from Base 8 to Base 10 Convert to base 10. Solution:

Slide 4-19 Copyright © 2005 Pearson Education, Inc. Example: Converting from Base 5 to Base 10 Convert 42 5 to base 10. Solution:

Slide 4-20 Copyright © 2005 Pearson Education, Inc. Example: Convert to Base 3 Convert 342 to base 3. Solution: The place values in the base 3 system are …, 3 6, 3 5, 3 4, 3 3, 3 2, 3, 1 or …729, 243, 81, 27, 9, 3, 1. The highest power of the base that is less than or equal to 342 is 243.

Slide 4-21 Copyright © 2005 Pearson Education, Inc. Example: Convert to Base 3 continued Successive division by the powers of the base gives the following result.

Slide 4-22 Copyright © 2005 Pearson Education, Inc. Example: Convert to Base 3 continued The remainder, 0, is less than the base, 3, so further division is necessary.

Slide 4-23 Copyright © 2005 Pearson Education, Inc. Computers Computers make use of three numeration systems  Binary  Octal  Hexadecimal

Slide 4-24 Copyright © 2005 Pearson Education, Inc. Numeration Systems Binary system  Base 2  It is very important because it is the international language of the computer.  Computers use a two-digit “alphabet” that consists of numerals 0 and 1. Octal system  Base 8 Hexadecimal system  Base 16

Copyright © 2005 Pearson Education, Inc. 4.4 Computation in Other Bases

Slide 4-26 Copyright © 2005 Pearson Education, Inc. Addition An addition table can be made for any base and it can be used to add in that base. Base 5 Addition Table

Slide 4-27 Copyright © 2005 Pearson Education, Inc. Add Solution: From the table = 12 5 Record the 2 and carry the Example: Using the Base 5 Addition Table

Slide 4-28 Copyright © 2005 Pearson Education, Inc. Example: Using the Base 5 Addition Table continued Add the numbers in the second column, ( ) = = Record the The sum is

Slide 4-29 Copyright © 2005 Pearson Education, Inc. Subtraction Subtraction can also be performed in other bases. When you “borrow” you borrow the amount of the base given in the subtraction problem. Example: If you are subtracting in base 5, when you borrow, you borrow 5.

Slide 4-30 Copyright © 2005 Pearson Education, Inc. Multiplication Multiplication table for the given base is extremely helpful. Base 5 Multiplication Table x

Slide 4-31 Copyright © 2005 Pearson Education, Inc. Example: Using the Base 5 Multiplication Table Multiply 12 5 x 3 5 Solution: Use the base 5 multiplication table to find the products. When the product consists of two digits, record the right digit and carry the left digit.

Slide 4-32 Copyright © 2005 Pearson Education, Inc. Example: Using the Base 5 Multiplication Table continued Record the 1 carry the x (3 5 x 1 5 ) = 4 5 Record the x The product is 41 5.

Slide 4-33 Copyright © 2005 Pearson Education, Inc. Division Division is carried out much the same way as long division in base 10. A division problem can be checked by multiplication.  (quotient divisor) + remainder = dividend

Copyright © 2005 Pearson Education, Inc. 4.5 Early Computation Methods

Slide 4-35 Copyright © 2005 Pearson Education, Inc. Early Civilizations Early civilizations used a variety of methods for multiplication and division. Multiplication was performed by duplation and mediation, by the galley method, and by Napier rods.

Slide 4-36 Copyright © 2005 Pearson Education, Inc. Duplation and Mediation Duplation and mediation uses a pairing method for multiplication. Example: Multiply using duplation and mediation. Solution: Write 13 and 22 with a dash to separate. Divide the number on the left in half, drop the remainder and place the quotient under the 13. Double the number on the right, and place it under the 22.

Slide 4-37 Copyright © 2005 Pearson Education, Inc. Duplation and Mediation continued 17 – 22 8 – 44 Continue this process until a 1 appears in the left hand column. 17 – 22 8 – 44 4 – 88 2 – – 352 Cross out all the even numbers in the left-hand column and the corresponding numbers in the right-hand column. 17 – 22 8 – 44 4 – 88 2 – – 352

Slide 4-38 Copyright © 2005 Pearson Education, Inc. Duplation and Mediation continued Now, add the remaining numbers in the right- hand column, obtaining = 374. To check = 374

Slide 4-39 Copyright © 2005 Pearson Education, Inc. The Galley Method The Galley method is also referred to as the Gelosia method. This method uses a rectangle split into columns and rows with each newly-formed square split in half by a diagonal.

Slide 4-40 Copyright © 2005 Pearson Education, Inc. Example: The Galley Method Multiply Solution: Construct a rectangle consisting of 3 columns and 2 rows. Place the 3-digit number above the boxes and the 2- digit number on the right of the boxes. Place a diagonal in each box. Complete by multiplying.

Slide 4-41 Copyright © 2005 Pearson Education, Inc. Example: The Galley Method continued Add the numbers along the diagonals. The number is read down the left-handed column and along the bottom, as shown by the arrow. The answer is 27,

Slide 4-42 Copyright © 2005 Pearson Education, Inc. Napier Rods John Napier developed in the 17 th century. Napier rods, proved to be one of the forerunners of the modern-day computer. Napier developed a system of separate rods numbered 0 through 9 and an additional strip for an index, numbered vertically 1 through 9.  Each rod is divided into 10 blocks. Each block below contains a multiple of a the number in the first block, with a diagonal separating its digits. The units are placed to the right of the diagonals and the tens digits to the left.

Slide 4-43 Copyright © 2005 Pearson Education, Inc. Example: Napier Rods Multiply 6 284, using Napier rods. Solution: Line up the rods 2, 8, 4, using 6 as the index. To obtain the answer, add along the diagonals as in the galley method. Thus, =