All posts by mathconfidence

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

Student work: How much is 12/0?

image

So how much is 12/0?  Go here to ask Google’s calculator: Google Calculator
G
oogle says Infinity

Now try the calculator from Web 2.0 Calculator
W
eb 2.0 says “Error: Divide by 0”

Desmos says “Infinity”

went through a lot of online calculators until I found this: http://www.calculator-tab.com/.  It says error and also says division by zero is not defined

Wolfram Alpha says “complex infinity”

Try your cell phone calculator(s) and post any other interesting answers here by leaving a comment…this student meant to write Undefined but wrote something super close 🙂