I'd say that if what you are doing isn't working, ie they aren't making progress, then do something different. Go and visit your FS and see what they do. Get out some practical tasks, weighing and measuring will do to aid counting as well. Leave them alone to get on with some work all by themselves. Have a bonfire of boring and dull and useless springboard nonsense! They are getting access to the curriculum in the sense they are getting all subjects at their level. That is all that is required of you.