The Decimal Number System Chapter 1 The Decimal Number System

The System Decimal refers to 10 10 symbols specifically 0 – 9 Example In the number 5,264 What weight does the 2 have What weight does the 4 have What weight does the 5 have What weight does the 6 have

The System Bill R. Deem and Tony Zannini Electronics and Computer Math, Eighth Edition Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.

Decimal Fractions A fraction with either Examples Ten or a multiple of ten as the denominator 10, 100, 1000, etc Examples 9 thousands = 9/1000 0.00039 = 3.9/10000 = 39/100,000 = 390/1M 57.045 = 57 45/1000 27 7/100 = 27.07

Rounding Off Numbers Common in problem solving Examples Simplifies calculation of approximate answer Used to eliminate precision that exceeds resolution of accuracy Examples Round 72, 348 to nearest tens = 72,350 Round 47.062 to nearest tenth and ten Yields: 47.1 and 50

Operations on Signed Numbers Addition & Subtraction Signed numbers per Number Line 6-3 = 3 OR 6 + (-3) = 3 Multiplication and Division Few and simple rules for sign numbers

Operations on Signed Numbers Multiplication and Division Rules for Signed Numbers ( + ) * ( + ) = ( + ) ( + ) * ( - ) = ( - ) ( - ) * ( + ) = ( - ) ( - ) * ( - ) = ( + ) Change denominators to reciprocals and the same rules apply to division

Order of operations Definitions Order of Operations Mathematical Term - Quantity preceded by a ‘+’ or ‘-’ sign Mathematical Expression – quantity with one or more terms Order of Operations Without ( ) or other grouping signs Do multiplications/divisions first for all terms Then add/subtract the terms

Order of operations Order of Operations With ( ) or other grouping signs In the inner most grouping Do multiplications/divisions first for all terms Then add/subtract the terms Remove inner most grouping marks Repeat above step until resolved