Jumping Frogs

frogs

The aim of this puzzle is to switch the red frogs with the blue frogs according to the following rules:

  • The left set of frogs can only move right, the right set of frogs can only move left.
  • Frogs can move forward one space, or move two spaces by jumping over another counter.
  • The puzzle is solved when the two sets of frogs have switched positions.

How many moves does this puzzle take?

How about if we change the number of frogs? Can you find a rule for the number of moves it will take based on how many frogs there are?

NRich has an applet with nice graphics here, but you are allowed to go backwards in their version, so it is is best to use this one to help you count the moves.

For interested facilitators extra notes and the solutions are here.

Venn diagram mystery

john venn

Today we solved an intriguing homework riddle with the help of a Venn diagram.  We had clues such as

“Seven students in total have Maths homework but Miya isn’t one of them.”

and

“Rory has more homework than Aidan.”

Using all the clues, which you can find here, we were able to work out which students had which pieces of homework.

It was a nice challenge! The solution can be found here. This activity was originally found on the TES website.

Name that Polynomial

This game is thanks to David Bedford at the BCME Conference in Warwick.

One person writes down a polynomial with positive integer coefficients. Call it f(x) They then choose an integer that it bigger than all their coefficients. Call it n. They then calculate f(n) and give just n and f(n) to the second person.

The second person should be able to name that polynomial! How?

Example:

Given only n=8 and f(n) = 6855 how could you work out that the polynomial was

?

It might help to think about an example when n=10 first.

The third challenge – number spellings

Hello everyone … we hope you will enjoy working on the problem below from the UK and Kenya! Please post your comments below.

First think of an integer written out in letters e.g. sixteen.

Take the number of letters in this number e.g. 7

Write this number out e.g. seven

Take the number of letters in this number e.g. 5

Write this number out e.g. five

Take the number of letters in this number e.g. 4

Write this number out e.g. four

Now we have converged to the number four.

Try this process with other numbers and see what happens.

Is it the same in other languages?

You may want to use the power of Python programming language to explore this further. You can make the Trinket below fullscreen by clicking on the three parallel lines in the top left corner and then clicking fullscreen (and do this again to stop it being fullscreen).

What day of the week …

… will the 28th of July 2061 be?  (Next predicted sighting of Halley’s comet)

… was the 4th of April 1965? (Robert Downey Jr ‘s birth)

… was the 17th of July 1789? (Prise de la Bastille)

We puzzled over these two questions having to think about where to start, the number of days in each month, and the rules for leap years.

It was fun to try different strategies by hand, but then we used the mod function and the floor function in Zeller’s algorithm to find quickly the day of the week for any date.

days of the week

Chaos Theory

rabbits

Today we explored one of the most famous recursive sequences called The Logistic Map.

logistic map equation

Try this activity leading on to exploring the sequence on Geogebra. There are Geogebra instructions here if you get stuck.

We were inspired for this activity by this amazing video from Ben Sparks on Numberphile. It explains how this activity links to one of the Feigenbaum constants, pseudo ramdom numbers and Chaos Theory. Definitely worth watching!

Möbius Bands

mobius

The first question of today is how many sides a piece of paper has. So the answer is 2 of course. Now we want to find a way of folding the paper in such a way that there is only one side. One way to verify this is to take a pen and colour the folded piece of paper. If you do not need to turn the piece of paper around, there is only one side. The method to do this is to twist the piece of paper by half a turn and you will obtain a möbius band.

This is all explained in this presentation from Suffolk maths, that also contains a brilliant exploration table. Your challenge is to fill in the first three lines and to come up with three other results to add to the table below.

mobius table

Good luck!

Cube buildings

cube building

We used this website to solve a series of challenges where you start with front, side and top elevations to build the full picture of 3D shape – building up to using only two views and silhouettes.

Notes on the website
– You need to click once for adding a cube and hold the clicker down a bit longer to clear.
When you press check, the tick is red if it is wrong, yellow if it works, but there could be fewer cubes, and green when it is correct and the minimum number of cubes have been used.