Are Tesco school vouchers worth it

I have two young kids & collect the vouchers for school equipment from tesco at each shop. When I read the reverse of the voucher it says that the monetary value of each voucher is 0.0001 cent. Does anybody know what the value each voucher is worth to the schools. I think that the supermarkets should be doing a lot more to support schools in the area after all they are taking huge profits from
from communities. It is also annoying to see the money wasted by the current & previous government & then to be dropping kids off at a prefab for their education.