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Number Play

Checkpoint: sums, squares and sequences

Five questions on the last five ideas. Feedback comes right away. Retry whenever you want.

You add 10 odd numbers and 3 even numbers. Is the sum odd or even?

A 3 by 3 magic square has 24 in the centre. What is its magic sum?

5 beats give 8 rhythms. 6 beats give 13 rhythms. How many rhythms have 7 beats?

In A + A + B = AA, what is B?

Which expression is always odd, for every whole number n?

0 of 5 answered

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This track

  1. 0 Start here
  2. 1 What a digit sum remembers
  3. 2 Why adding the digits knows anything
  4. 3 Odd and even, multiplied
  5. 4 Turn it round and subtract
  6. 5 Several clues at once
  7. 6 The case that breaks it
  8. 7 Saying why, in order
  9. 8 Odd and even, added
  10. 9 Magic squares
  11. 10 Counting rhythms
  12. 11 Letters for digits
  13. 12 Even or odd expressions
  14. 13 Checkpoint: sums, squares and sequences
  15. 14 The big picture
  16. 15 Track quiz

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