There are a number of different ways in which you, as the teacher, might use NRICH solutions as part of the lesson itself and these are outlined in our Celebrating Solutions Feature.
The tasks below have some published solutions which are not completely correct. Challenge your learners to find what is not quite right in each one and to explain why, or how they know.
problem
Favourite
Inside triangles
Age
5 to 7
Challenge level
How many different triangles can you draw on the dotty grid which each have one dot in the middle?
problem
Favourite
School fair necklaces
Age
5 to 11
Challenge level
How many possible symmetrical necklaces can you find? How do you know you've found them all?
problem
Favourite
Reflecting squarely
Age
11 to 14
Challenge level
In how many ways can you fit all three pieces together to make shapes with line symmetry?