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# Sets and Symbols

## Whole numbers, integers, rational numbers, and irrational numbers

Levels are CK-12's student achievement levels.
Basic Students matched to this level have a partial mastery of prerequisite knowledge and skills fundamental for proficient work.
At Grade (Proficient) Students matched to this level have demonstrated competency over challenging subject matter, including subject matter knowledge, application of such knowledge to real-world situations, and analytical skills appropriate to subject matter.
Advanced Students matched to this level are ready for material that requires superior performance and mastery.

## Classify Real Numbers

by CK-12 //basic
Learn to classify real numbers.
MEMORY METER
This indicates how strong in your memory this concept is
4
• Video

## Identifying Rational Numbers

by CK-12 //basic
Explains how to find out if a number is rational or not.
MEMORY METER
This indicates how strong in your memory this concept is
5