'Try it' not working? See note below.

Week 225 - 10 July 2023 - Counting words and subtracting numbers

• Task 1 - Max words

• Task 2 - Left right sum diff

Week 224 - 3 July 2023 - Strings and sequences

• Task 1 - Special notes

• Task 2 - Additive number

Week 223 - 26 June 2023 - Counting primes and maximising cash

• Task 1 - Count primes

• Task 2 - Box coins

Week 222 - 19 June 2023 - Members’ week

• Task 1 - Matching members

• Task 2 - Last member

Week 221 - 12 June 2023 - Good strings and hidden sequences

• Task 1 - Good strings

• Task 2 - Arithmetic subsequences

Week 220 - 5 June 2023 - Common characters and squareful sequences

• Task 1 - Common characters

• Task 2 - Squareful

Week 219 - 29 May 2023 - Any more fares, please?

• Task 1 - Sorted squares

• Task 2 - Travel expenditure

Week 218 - 22 May 2023 - Multiply three and binary matrix

• Task 1 - Maximum product

• Task 2 - Matrix sum

Week 217 - 15 May 2023 - Sorted them both

• Task 1 - Sorted matrix

• Task 2 - Max number

Week 216 - 8 May 2023 - Alphabetical exercises

• Task 1 - Registration number

• Task 2 - Word stickers

Week 215 - 1 May 2023 - Adopt a chilly ghost

• Task 1 - Odd one out

• Task 2 - Number placement

Week 214 - 24 April 2023 - All about points

• Task 1 - Rank score

• Task 2 - Collect points

Week 213 - 17 April 2023 - Evens go first and untangling the route

• Task 1 - Fun sort

• Task 2 - Shortest route

Week 212 - 10 April 2023 - Lead to Gold and 1 2 3

• Task 1 - Jumping letters

• Task 2 - Sequential substrings

Week 211 - 3 April 2023 - Striped arrays and balanced splits

• Task 1 - Toeplitz matrix

• Task 2 - Split same average

Week 210 - 27 March 2023 - Kill and collide!

• Task 1 - Kill and win

• Task 2 - Number collision

Week 209 - 20 March 2023 - An abc and @emails

• Task 1 - A 3-letter alphabet

• Task 2 - Merging emails

Week 208 - 13 March 2023 - Matching strings and missing numbers

• Task 1 - Minimum index sum

• Task 2 - Duplicate and missing

Week 207 - 6 March 2023 - All on the same line, and am I being cited?

• Task 1 - Linear words

• Task 2 - The H-index for citations

Week 206 - 27 February 2023 - Shortest time and max of mins

• Task 1 - Measuring the gaps

• Task 2 - Array pairings

Week 205 - 20 February 2023 - Third highest and maximum xor

• Task 1 - Third highest value

• Task 2 - Maximum xor

Week 204 - 13 February 2023 - Climbing or falling and reshaping the matrix

• Task 1 - Uphill or downhill?

• Task 2 - Reshape matrix

Week 203 - 6 February 2023 - Quads and directory enquiries

• Task 1 - Special quads

• Task 2 - Copy folders

Week 202 - 30 January 2023 - Three odd things in the valleys

• Task 1 - Three odd things

• Task 2 - Find the valleys

Week 201 - 23 January 2023 - Missing numbers and piles of pennies

• Task 1 - Missing numbers

• Task 2 - Piles of pennies

Note: Occasionally older 'try it' buttons don't work, because of later changes to the way this website works. If you let me know (email link) I will (try to) fix them.