Class Topics: 11.01.11

In EDM today, we continued our work with unit rates.  We began by completing a Quick Check on unit rates which will be posted to GBW.  Students were given their Unit Three Formative Pretests back today in preparation for next week's Unit Three Summative Assessment.  Look for a blank copy of the pretest along with an answer key on the blog.


In Pre-Algebra today, we continued our work with square roots in class.  The difference between today's lesson and yesterday's is that we did not work with perfect squares but rather began to work with square roots that did not work out to be perfect.  Refer to the example of an Application Skill below.

PROBLEM

You want to sew a fringe on a square tablecloth with an area of 500 square inches. Calculate the length of each side of the tablecloth and the length of fringe you will need to the nearest tenth of an inch.

UNDERSTAND THE PROBLEM

First find the length of a side. Then you can use the length of a side to find the perimeter, the length of fringe around the tablecloth.

MAKE A PLAN

The length of a side, in feet, is the number that you multiply by itself to get 500. To be accurate, find this number to the nearest tenth. If you do not know a step-by-step method for finding   500, use guess and check.

SOLVE

Because 500 is between 222 and 232, the square root of 500
is between 22 and 23.To round to the  nearest tenth, look at the next decimal place.
Consider 15.85.  15.85 squared = 251.2225
The square root is lower than 15.85, so round down.
To the nearest tenth,    the square root of 250 is about 15.8. 
The length of each side of the garden is about 15.8 ft.

Squares and Square Roots