Sunday, April 12, 2020

Drafter's Puzzle #2

A solid figure cut out of a cube looks like this in 2 dimensions when viewed from the front, back, and top.  Notice that it has a horizontal edge visible from the front but not from the top.  What could the solid look like?


Notice that it cannot look like this.  Otherwise we would see an edge from the top too!


What does the solid look like?  There are various possibilities. Click HERE for the solution.





Thursday, April 9, 2020

Spatial thinking challenge

The figures below are all cut out of identical cubes.


The diagram below shows the front view of the figures in two dimensions.


Question:  What would the figures look like from the top in two dimensions?  Strangely, four of them look the same from above.  Which one is different?

For the solution, click HERE.

Tuesday, March 24, 2020

The Funny Calculator

A calculator has these buttons:





Just like a “normal” calculator,  

When you type 1 x 10, it says 10.
When you type 1 + 10, it says 11.

But…

When you type 1 + 1, it says 10.
When you type 10 + 10, it says 100.

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Using this information alone:

How would you count from one to four?  

What would the calculator say if you typed in 100 10 ?
    

Extending the pattern:


 Can you extend the pattern to count up to twenty?

What would the calculator say if you typed in 0.1 + 0.1?

What would the calculator say if you typed in 0.1 x 10 ?

What would the calculator say if you typed in 111 + 111 ?

What would the calculator say if you typed in 111 x 10 ?


For the solution, click HERE.




Saturday, March 21, 2020

Counting triangles!

How many triangles are there in this picture?

It's not so easy.....

Did you say 7?  If so, you're right!

Watch this interactive video to practice organizing your thoughts when you solve counting problems: