Less than? Before? Minus one? What does that mean?

Observation of learners over the past years have shown that children in the tail end often have severe limitations in their vocabulary and understanding of basic concepts in size, order, and direction among others. Concepts need to be taught and repeated before internalisation occurs and application to problems can happen. How can I do this while meeting the demands of a full schedule? I know about apps, but frankly many are naff or incomplete for my needs. The many resources available from teachers around the world are often too babyish for my year 4/5/6 learners because these concepts should be developed in kindergarten or the first couple of years at primary school.

My solution is a series of semi open-ended tasks dubbed "Knowledge Cards"...until I can think of a cooler name. These are used with maths materials or other realia around the classroom to reinforce concepts in the learner's mind. Learners are also supposed to describe what they have done aloud in a Maths Vlog to aid in both reinforcing concepts and learning how to use the vocabulary verbally.

So far there has been a positive response to the cards I have developed. There are still some cards that I would like to make for both simple and more advanced maths concepts such as dividing/sharing items and part-whole number relationships.