Curriculum › Math ›Grade 4

Grade 4 Math · Level 2, Multiplication, Division & Factors

Exponents & Perfect Squares

How the lesson starts: Exponents & Perfect Squares

1. Wizard Wren's spell

   Welcome to the tower! Wizard Wren writes a spell: 2 × 2 × 2 × 2 × 2. Her spell book is running out of room! Is there a shorter way to write it? Let's learn some number magic!

2. Square magic

   First, a small spell: 4². That means 4 × 4. Look: 4 rows of 4 stars make a perfect square! 4² = 16. That's why we say 4 squared. The tiny 2 means two copies of 4.

3. A tiny number on top

   Back to Wren's long spell. Count the 2s: there are five. So write a big 2 with a tiny 5 on top: 2⁵. The big 2 is the base. The tiny 5 is the exponent. It counts the copies. 2⁵ = 32, not 2 × 5!