### Eight Dominoes

Using the 8 dominoes make a square where each of the columns and rows adds up to 8

### Score

There are exactly 3 ways to add 4 odd numbers to get 10. Find all the ways of adding 8 odd numbers to get 20. To be sure of getting all the solutions you will need to be systematic. What about a total of 15 with 6 odd numbers?

### Medal Muddle

Countries from across the world competed in a sports tournament. Can you devise an efficient strategy to work out the order in which they finished?

# Inspector Morse

##### Age 11 to 14Challenge Level

Copying and pasting the article into a word processor and then using the "replace" facility will quickly tell you how many of each letter there is.

 A B C D E F G H I J K L M .- -... -.-. -.. . ..-. --. .... .. .--- -.- .-.. -- 4 6 8 5 1 6 7 4 2 10 7 6 6 N O P Q R S T U V W X Y Z -. --- .--. --.- .-. ... - ..- ...- .-- -..- -.-- --.. 4 9 8 10 5 3 3 5 6 7 8 10 8

Is there much variation in the order of frequency of use of letters you found in the article and what is implied by the choice of symbols and time values used by Morse? Is E the most frequent letter in the article and I the next?

Your coded message might be longer or shorter than when you use Morse but it is just one possible message. How would you compare the two systems more generally?