‘Practic-All’

Pragmatic tools and ideas for the classroom

Numeracy Task 2 – Flipping Hidden Cups

Four CupsA round table has four deep pockets equally spaced around its perimeter. There is a cup in each pocket oriented either up or down, but you cannot see which. The goal of the game is to get all the cups ‘up’ or all the cups ‘down’. You do this by reaching into any two pockets, feeling the orientation of the glasses, and then doing something with them, (you can flip one, two, or none). However, as soon as you take your hands out of the pockets the table spins in such a way that you can’t keep track of where the pockets you have visited are. If the four glasses ever get oriented all up or all down a bell rings to signal you are done. Can you guarantee that you will get the bell to ring in a (maximum) finite number of moves, and if so, how many?

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You can find out more about Numeracy Tasks in my ‘Pair-a-Dimes’ blog.
I will tag all tasks like this with Numeracy so that they are easy to find in one location.

Please feel free to post questions or your best answer in a comment… but do not ruin the challenge for others by explaining how you got to that answer here! If you feel compelled to share your method, please do so by contacting me. Thanks!

January 27, 2007 Posted by | contact, David Truss, lessons, Math, Numeracy, Pair-a-Dimes | 1 Comment

Numeracy Task 1 – The Glass Orb Drop

 

'Sphere_2720' by doviendeYou have two glass orbs of equal strength and a 40 story building.
Your task is to determine the highest floor from which you can drop an orb without it breaking.
What is the least number of drops required to do this?
Both orbs may be broken in order to determine your answer.
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You can find out more about Numeracy Tasks in my ‘Pair-a-Dimes’ blog.
I will tag all tasks like this with Numeracy so that they are easy to find in one location.

Please feel free to post your questions or best answer in a comment… but do not ruin the challenge for others by explaining how you got to that answer here! If you feel compelled to share your method, please do so by contacting me. Thanks!

Image: ‘Sphere_2720’by doviende

January 27, 2007 Posted by | contact, David Truss, lessons, Math, Numeracy, Pair-a-Dimes | 1 Comment

Questions about me, and this site…

Who am I?
A husband, a parent…
An educator, a student…
A thinker, a dreamer…
An agent of change.

What is this blog about?
I have been compiling an extensive de.licio.us account and I find that I need a place to put down my practical ideas that dart across my mind when I find a ‘useful’ link worthy of bookmarking.

Where else do I blog?
My ’Pair-a-Dimes for Your Thoughts’ on DavidTruss.com has a philosophical bent to it. My thoughts on education, learning and technology.

When and why did I start this? (Don’t bother with this link, just a little history of where this all started.)
My David Truss – Practic-All blog started on Bloglines, but I found wordpress to be more… practical. I just wanted a space to put down lessons, activities and strategies that didn’t seem to fit on my ‘Pair-a-dimes’ site. I hope others will find it practical too!

Feel free to Contact Me. I spend more time at my ’Pair-a-Dimes for Your Thoughts’ blog than I do here.

Dave.

January 2, 2007 Posted by | About Me, contact, David Truss, del.icio.us, education, learning, links, Pair-a-Dimes, teaching | , , , | Comments Off on Questions about me, and this site…