Go you child’s pace. Bug if you rally want to move to level b, you could as it also starts from the beginning.
Technically, you have until about grade 9 to start algebra. So, assuming edition 1 of rightstart… You have 9 years (k-8) to do 7 levels… A,b,c,d,e,g, videotext a. There really is no panic, and you can’t really push math anyway…