National Wildfire Coordinating Group

1.0 Back to the Basics - Introduction


The material in this chapter describes the use of numbers in basic arithmetic, including addition, subtraction, multiplication, division, order of operation, exponents, rounding, significant digits, and decimal places. Fractions and ratios are also examined. A text description accompanies a graphic illustration and sample problem to explain each concept. Exercise problems give you a chance to practice your skills.


Recall that numbers increase from zero in both the positive and negative directions, extending onward essentially forever. This concept can be illustrated by a line with arrows pointing in both directions, extending on to infinity. The numbers to the right of the zero are called positive and the numbers to the left are negative.