Domino tetrads
There are 28 dominoes in a set, which can be arranged in seven sets of four making a complete link, like the one below.
Image

Is it possible to use all 28 dominoes arranging them in this way? What patterns can you see in the solution(s) and can you explain them? How do you know that you have all the solutions? 
You may find our Dominoes Environment useful for working on this problem.
Printable NRICH Roadshow resource.
There are seven doubles and seven sets of four to organise!
A solution has been offered by Jonathan R. and his friends Jonathan
M. and Matthew G. of Steyning Saint Andrews C.E Primary School.
There is more than one solution but it needs a means of
representing each arrangement in order to show what is happening
and to identify possible avenues to further solutions. There is
still a lot more in this problem if you are prepared to have a go
but thanks for this start Jonathan.
Together my friends and I solved this puzzle. Here is our solution:
1) yes you can make the squares with all the pieces
2) in every square you have a double at the top .
3) we could not find any other solutions to this puzzle and we don't think itis possible for another solution.