# Introduction to Algebra IV - At Right Angles Pullout

This is the fourth article in the series, Introduction to Algebra. The first one looked at algebra as a ‘pattern language’ and focused on noticing patterns and expressing patterns using terms and expressions. The second one looked at algebra as a ‘design language’ and focused on expressing designs using algebraic language. The third one explored solving simple equations using the ‘balance approach’ and the ‘machine approach.’ However, the topic of equations is vast and gets steadily more complex as the student progresses through higher algebra. Similarly, the topic of solving and simplifying expressions of higher degree steadily grows in complexity.

The precursor to simplification, factorisation and expansion of expressions of higher degree is a study of the laws of indices and basic identities. The index laws come into play while using large numbers as well, which are often written in scientific notation and involve powers. When these numbers are multiplied, divided or raised to a power, the laws of indices are applied.

In this article, we study indices (only positive whole number indices) and basic identities. The article does not go into the application of these concepts in problem situations.