This lesson simplifies and operates on square roots and cube roots.

1. Skill 6 Square Roots and Cube Roots
The idea of square roots and cube roots is related to the idea of exponents and multipllcation.

2. Notice the numbers in the multiplication table below . The numbers in yellow are
numbers multiplied by themselves. 2 x 2 3 X 3 4 X 4 The products are called
perfect squares. See the list on the previous slide. To find the square root, means
to name the number that you multiply by itself to give the number in yellow.
Square root of 25 is 5 because 5 X 5 is 25. We have a special symbol to replace the words square
root.

4. First, we need to simplify square roots. This process is like simplifying a fraction.
It should be done for all problems with roots.
The big idea is to leave no number with a perfect square factor under the
Radical (square root) sign.

5. Simplify.
Practice on page 65 in the book. There are several ways to factor the numbers.

6. You may likely be asked to multiply two square roots.

7. You should also be prepared to add, subtract or multiply square roots.
Square roots must match exactly to be added or subtracted.

11. We can also simplify cube roots by factoring the number under the radical sign into
factors which are cubes like 1 (NOT THIS ONE), 8, 27, 64, 125, etc.
Factor 16 into 8 times 2
The cube root of 16 is 2
Factor 54 into 27 times 2.
The cube root of 27 is 3.
Try problems on page 67 in the book.

12. A problem like number 1 below was on a recent test. See the next slide for answers.
From page 67a….

14. More practice from the book….page 67a with answers below.
Try page 67b…..