Chapter 1: Decimals, Fractions, and Percents

Decimals, fractions and percents

A source-bound narrated opening with a worked example, an eight-second thinking pause, a checked result, English captions, and a transcript.

Read the transcript Download the video Narration credits and licences

You probably already know quite a bit about decimals based on your experience with money. Suppose you buy a sandwich and a bottle of water for lunch. If the sandwich costs $$3.45$ , the bottle of water costs $$1.25$ , and the total sales tax is $$0.33$ , what is the total cost of your lunch?

A vertical addition problem shows $3.45 for a sandwich, $1.25 for water, and +$0.33 for tax. The bottom total is $5.03.

The total is $$5.03.$ Suppose you pay with a $$5$ bill and $3$ pennies. Should you wait for change? No, $$5$ and $3$ pennies is the same as $$5.03.$

Because $100 pennies equals $1,$ each penny is worth $\frac{1}{100}$ of a dollar. We write the value of one penny as $$0.01,$ since $0.01 = \frac{1}{100} .$

Corequisite Skills for Introductory Statistics is a custom course edition compiled for Introductory Statistics corequisite courses from OpenStax Contemporary Mathematics, Elementary Algebra 2e, Intermediate Algebra 2e, Prealgebra 2e. Content by OpenStax is reproduced as published, apart from any corrections recorded for this edition. Sections are renumbered to follow the course outline. The course outline is adapted from Larry Green's Support Course for Elementary Statistics (LibreTexts, https://stats.libretexts.org/Bookshelves/Introductory_Statistics/Support_Course_for_Elementary_Statistics), used under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Lessons 2.4 and 6.7 are written for this edition by XYZ Homework. Every OpenStax lesson is abridged to the subsections and practice exercises this course uses. Lessons are headed with their course titles, not the source section titles. Access the complete originals free at openstax.org. License: CC-BY-NC-SA-4.0.