Illustrative Mathematics
Converting Decimal Representations of Rational Numbers to Fraction Representations
A rational number is a ratio of two integers. Discuss with your class how to convert the rational numbers of repeating decimals to fractions. A good commentary on letting x equal the repeating decimal and multiplying each side of...
Illustrative Mathematics
Comparing Rational and Irrational Number
Algebra learners must know how to use rational numbers to approximate irrationals. This resource asks participants to decide which number is larger without using a calculator. It makes a great exercise to use as a five-minute transition...
Illustrative Mathematics
Comparing Temperatures
Which is colder -12 or -18? Temperature is natural real-world application of ordering rational numbers. It's also fun to talk about the lowest recorded temperature on Earth. Take the time to discuss this inquiry with your class.
Illustrative Mathematics
Irrational Numbers on the Number Line
There are four irrational numbers that participants need to graph. Pi(π), -(½ x π), and √17 are easy to approximate with common rational numbers. On the other hand, the commentary describing the irrational number 2√2 is not...
Oregon Department of Education
Building Number Sense
It's never too early to begin a child's math education. This collection of fun hands-on activities engage youngsters in building their number sense as they learn how to count objects, identify numerals, compare amounts, and much more.
Illustrative Mathematics
Placing a Square Root on the Number Line
There are many ways to approach finding the rational approximation of an unknown square root. Here is a problem that will help math learners make a connection between square roots and their order on a number line. As usual, determine two...
5280 Math
Decimal Patterns
Find patterns in the process instead of the result. Learners convert series of decimals and fractions identifying patterns along the way. The lesson includes nine problem tasks with progressively more involved patterns.
Cut the Knot
What's a Rational Number?
This question is answered by discussing and comparing rational and irrational numbers. For more advanced levels of Algebra, there are sections that discuss different lemmas of rational numbers and give their proofs.
Texas Instruments
Texas Instruments: Comparing and Ordering
In this activity, students can use a number line to locate and compare rational numbers.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Rational Numbers
Math Forum response addressing how many elements are in the set of rational numbers. Responses investigate the countability of sets, and how sets with an infinite number of elements can be counted and compared to other "infinite sets."