Input is foundational to learning anything. So often we spend excessive time testing a child’s knowledge before he has had an opportunity to actually learn the information. When teaching something new, you should keep the amount of math facts or spelling words, for example, to about 5 at a time. Through out the day, input these facts or words to your child - visually and auditorilly.  It will only take a minute or two to input to the child then the he can return to what he was doing. Over time you can add additional facts or words.