#### You may also like ### Prompt Cards

These two group activities use mathematical reasoning - one is numerical, one geometric. ### Exploring Wild & Wonderful Number Patterns

EWWNP means Exploring Wild and Wonderful Number Patterns Created by Yourself! Investigate what happens if we create number patterns using some simple rules. ### Worms

Place this "worm" on the 100 square and find the total of the four squares it covers. Keeping its head in the same place, what other totals can you make?

# Calendar Patterns

##### Age 7 to 11 Challenge Level:

Anil (Irmak Primary School, Turkey) explored some adding patterns:

$1 + 8 = 9$
$2 + 9 = 11$
$3 + 10 = 13$
$4 + 11 = 15$
$5 + 12 = 17$
$6 + 13 = 19$
$7 + 14 = 21$
$8 + 15 = 23$

Alice from Perse School for Girls spotted a pattern:

There is a pattern, it's that the two numbers diagonal to each other added together make the same number as the other pair of diagonal numbers make.

Chris found another pattern using multiplication:

If you cross multiply the set of four numbers, their difference is always $7$.
$1 \times 9 = 9$ and $2 \times 8 = 16$, difference $= 7$
$3 \times 11 = 33$ and $4 \times 10 = 40$, difference $= 7$
$15 \times 23 = 345$ and $16 \times 22 = 352$, difference $= 7$ etc...

If you discovered any other patterns, then do let us know. Please don't worry that your solution is not "complete" - we'd like to hear about anything you have tried.