In teaching procedural and factual knowledge, ensure the students gets to automaticity. Explain to students that automaticity with procedures and facts is important because it frees their minds to think about concepts.
Fluency is about instant recall, but should not just be about rote learning and is not just limited to recalling a set of known facts. Children need to be encouraged to notice key aspects of the mathematical structure in order to develop fluency with their number facts, derive further numbers facts, and identify inaccuracy in their work.
For more support in developing fluency, please have a look at the recent NCETM feature on developing fluency in year 1 and 2 addition and subtraction facts: https://www.ncetm.org.uk/resources/50006