1. Objective: Students will be able to use roots to estimate solutions.
8-2 Estimating Roots
Objective: Students will be able to use roots to estimate solutions.
8.NS.2 Use rational approximations of irrational numbers to compare the size of irrational numbers, locate them approximately on a number line diagram, and estimate the value of expressions (e.g., π2). For example, by truncating the decimal expansion of √2, show that √2 is between 1 and 2, then between 1.4 and 1.5, and explain how to continue on to get better approximations.
8.EE.2 Use square root and cube root symbols to represent solutions to equations of the form x2 = p and x3 = p, where p is a positive rational number. Evaluate square roots of small perfect squares and cube roots of small perfect cubes. Know that √2 is irrational.

2. Do Now:

3. Algebra 2-1 Rational Numbers on a Number Line
Write The Following In Exponential Form Then Solve:
Algebra 2-1 Rational Numbers on a Number Line
4*4
3*3*3
5*5*5
6*6
7*7
-10*-10*-10
-2.5*-2.5
Harbour

4. Algebra 2-1 Rational Numbers on a Number Line
Squaring: to raise a number
to the second power
Cubing: to raise a number
to the third power.
Square Root: one of the two
equal factors of a number
Cube Root: one of the three
equal factors of a number
Harbour

5. Perfect Square: a rational number whose square root is a whole number
Perfect Cube: a rational number
whose cube root is
a whole number
Non-Perfect Square: a number
whose square root is not
a whole number
(decimal/fraction)
Non-Perfect Cube: a number
whose cube root is not
a whole number
(decimal, fraction)

6. Algebra 2-1 Rational Numbers on a Number Line
Find Each Square or Cube Root
Harbour

7. Perfect Square Roots
Perfect Cube Roots

8. Algebra 2-1 Rational Numbers on a Number Line
Estimating Square and Cube Roots:
You can estimate the value of a square or cube root by determining which two perfect squares or cubes the number falls in between.
Harbour

9. Algebra 2-1 Rational Numbers on a Number Line
Estimate
Harbour

11. Worksheets!
Homework 8-2
Pages All #’s

12. Exit Ticket:
After an accident, officials used the formula below to estimate the speed the car was traveling based on the length of the car’s skid marks. Where s represents the speed in miles per hour and m is the length of the skid marks in feet.
If a car leaves a skid mark of 50 feet, what was its approximate speed?