Terrible Quality of Education in SK

Recently, I was posted outside Canada for few years and relocated with my family (which included school aged kids). For most part my kids were doing okay with their academics and curricular. Once I enrolled them in their new schools (at their appropriate grade level), they started struggling. They found the math to be too difficult and their science skills were not up to expected grade level in their new school. I have been ashamed and appalled. A little bit of investigating made me conclude that the level and quality of education in the province is absolute crap. We had to spend significant amount of time and efforts just to bring them up to their average global grade level. One could blame the under funding in education, but there has to be something more to it. Why is our curriculum not at par with other Canadian provinces or western countries? While province may have underfunded, I know for a fact that significant chunk of our property taxes goes towards education.