All posts by mathconfidence

Get the Math and Get Points!

When putting the answer choices into the TI-84 we can see that the only match is II.

Analyzing a graph can teach students about the zeros or solutions of a function.  This function passes through the x-axis 3 times: at x = -2, x = 1 and x =3.   We can also use this question to talk about factoring, y-intercepts, end behavior and other cool Math ideas.  The process of elimination is very rewarding as compare/contrast is a great way to learn content and  metacognition.

I am in favor of students knowing the Math part of this for sure but with the TI-84 , they can get the Math and get points.  The 2 points on this type of question may make the difference between Pass and Fail and perhaps even high school graduation.     The problem below comes from the June 2015 Algebra I Regents.CC Alg I 0615 12 Graohing cubic


Screen for 12 Alg I Regent12 I Algebra I CCOption I is a NO GO so answers (1) and (3) are OUT.

12 I Algebra I CC part 1112 I Algebra I CC part 11 Graph
Option II looking good — it’s a keeper!! 

12 I Algebra I CC part 11112 I Algebra I CC part 111 Graph
Option III is a NO GO 








November 2015 Brain Teaser Solution

Which is greater, 2^1100 or 3^700?
Bonus: Approximately how many times greater is it (to the nearest 10)?
Both of these are too large to do on a calculator and will force the calculator into overflow.  So we have to come up  with another way to compare them rather than getting both actual values.
We can write them as:
(2^11)^100   and (3^7)^100 and just compare the
2^11   vs 3^7
2048 vs 2187
so 3^700 is the winner!!
Here is a link to the answer to the bonus
Thanks for solving

Now and Later: Get/Give 2 Copies of a Review Sheet

Now and Later

A review sheet is a gift and usually a preview of the exam!

if your teacher gives you a review sheet, do not write on it so you will be more likely to REDO the problems.
If you are a teacher, hand out 2 copies and/or post a copy on line so students can redo rather than just reading them over.

Study skills are different for Math than for other content areas…please practice now and then again later 🙂

October 2015 Brain Teaser Solution

Q: How many squares are on an 8 x 8 checkerboard?  10 x 10? How many rectangles?

8 x 8 There are:
64 1 x 1
49 2 x 2
36 3 x 3
25 4 x 4
16 5 x 5
9  6 x 6
4 7 x 7
1 8 x 8 for a total of 204 squares

For 10 x 10
100 1 x 1
81 2 x 2
64 3 x 3
49 4 x 4
36 5 x 5
25 6 x 6
16 7 x 7
9 8 x 8
4 9 x 9
1 10 x 10

for a total of 385 squares

The rectangle counting is significantly more challenging.
Click here for a beautiful explanation from Nigel Coldwell