In this second half of Class 6, we will investigate a few of Ruby's capabiities to complete advanced formatting and mathematical calculation.

1. MATH HACKS IN RUBY
Class 6a – Ruby Math

2. Introduction
 Ruby Basics
 Puts
 Gets
 Some basic math operations
 “+”, “-”, “*”, “/”
 Formatting and Advanced Math
 Line formatting (right/left justification, centering)
 Exponents, roots, the Math Object

3. Agenda
 Review the Assignment 3 solution
 Add formatting
 to make interface and output more attractive
 To make interface more intuitive
 To make output more functional
 Advanced Math
 Exponents and Roots
 Absolute and Modulus
 Math::pi and rand

4. Formatting
 Example – our class average assignment
 Preferred format/ line length of 60
Student Marks
Sam 75
Susan 78
George 87
Anne 92
Joe 67
_____ _____
Average 76.5

5. Demonstration
 IPO
 Input
 Processing
 Output
 Code

6. Ruby Math: Exponent and Root
 Exponent
 Notation a**b
 a to the power of b
 Example
 Root
 Using Math Object
 Math.sqrt(val)
 Using math formula
 x**0.5

7. Ruby Math: Absolute & Modulus
 Absolute
 Notation a=x-y.abs
 Example
 Modulus (gizinta, what’s left?)
 Notation a=x%y
 Example: Kids Inc. Summer Camp

8. Ruby Math: Random & Pi
 Random
 Use: rand(max_val)
 Result is zero based
 Example
 Math:Pi
 Use Math::Pi*(val)
 Example:Volume of a cylinder
 IPO first?

9. Summary
 Exponent (a**b)
 Root (sqrt or a**b/c.to_f)
 Absolute (abs)
 Modulus (a%b)
 Random (rand(x))
 Pi (Math::PI)

10. Project 1: Calculator/Converter
 Objectives
 Apply mathematical formulas to real problems
 Apply a programmatic approach to a solution
 Apply basic ruby mathematical operations
 Apply basic ruby formatting
 Grading – in 3 parts
 Due Date:Week of Nov 15
 NextWeek: Part of class for project work,
problems, challenges, ideas