Hilary and Steve have experience of mathematics in countries outside the UK. They have been involved in analysing maths curricula from around the world and comparing them with that of the UK, including those from such countries as India and Singapore.

Hilary and Steve have worked in co-operation with the Mathematical Association of Ghana to produce materials for Junior Secondary schools (JSS 1 - 3) in the country and have also produced similar materials for Caribbean schools.

Steve co-wrote the internationally best-selling Maths Pack /Maths Kit with Ron van der Meer which sold extensively in countries around the world.

Many of Hilary and Steve's books are published in several languages, including Welsh, German and Chinese.