Technical Mathematics (Chase)

This developmental-level mathematics textbook is intended for career-technical students. It was made possible by a grant from Open Oregon Educational Resources, which supports the development and implementation of high-quality materials at low or no cost to community college and university students.

I hope that this qualifies as a “high quality” textbook, and I hope that it brings a bit of fun to what can often be a boring or intimidating subject. Whether you are a student or instructor, I would love to hear your thoughts on the book and whether it works well for you. Feel free to let me know about any errors you find or suggestions for improvements.

The formatting was optimized for the web version of the textbook, and I know that the pdf versions look rough: strange indenting I can’t seem to fix, images that aren’t aligned properly, inconvenient page breaks, numbers appearing larger than the surrounding text, etc. I will try to clean up the formatting problems at some point, but it’s time for me to make the leap and get this thing out into the world.

Negative Numbers

Negative numbers are a fact of life, from winter temperatures to our bank accounts. Let’s practice evaluating expressions involving negative numbers.

Absolute Value

The absolute value of a number is its distance from . You can think of it as the size of a number without identifying it as positive or negative. Numbers with the same absolute value but different signs, such as 3 and -3, are called opposites. The absolute value of -3 is 3 , and the absolute value of is also 3.

We use a pair of straight vertical bars to indicate absolute value; for example, -3 = 3 and 3 = -3 .

Subtracting Negative Numbers The image below shows part of a paystub in which an $18 payment needed to be made, but the payroll folks wanted to track the payment in the deductions category. Of course, a positive number in the deductions will subtract money away from the paycheck. Here, though, a deduction of negative dollars has the effect of adding dollars to the paycheck. Subtracting a negative amount is equivalent to adding a positive amount.