The object of Sloyd as a means of education is two-fold: Firstly it is to form a practical contrast to the other instruction which is mainly of a one-sided theoretic character; it will thus set to work faculties in the child that would otherwise remain unused in school. Secondly it is to form the practical starting point of the other disciplines that will thus become object lessons in a deeper sense of the word than has been the case till now. Already for a long time it has been understood, to a certain extent, that nowadays, more than ever, the race in later life calls for a training by means of bodily labor already in childhood.Sloyd is still compulsory in Scandinavian education, so you can guess what our students are missing.
In a comment to an earlier post KP from VT noted his own difficulty with Algebra. My own response is related to this post, as Danish Sloyd recognized the use of woodshop as a means to establish relevance and purpose to all other subjects.
Teaching and learning math and algebra are significantly easier if done hands-on. My daughter learned Algebra in 6th grade at Clear Spring School using sticks. Many teachers have gone through the motions of teaching math while many students like yourself have been allowed to fall through the cracks. I was taught Algebra without ever learning that it could be useful for something. Having a clear use makes it interesting, relevant and much more easily learned. So I advise not giving up on Algebra, but teaching it in a manner that gives it relevance and use. Building a boat, for example.
Make, fix and create...