At every level, later math learning depends on earlier understanding. Previous research has found that the knowledge children have of number before they start school predicts their achievement throughout elementary school.

One critical aspect of mathematical development is cardinal-number knowledge (e.g. knowing that the word ‘three’ refers to sets of three things). But being able to count doesn’t mean the child understands this principle. Children who enter kindergarten with a good understanding of the cardinal principle have been found to do better in mathematics.

Following research indicating an association between children’s knowledge of number and the amount of number talk their parents engage in, a new study recorded parental interactions for 44 young children aged 14-30 months. Five 90-minute sessions, four months apart, were recorded in the children’s home, and each instance in which parents talked about numbers with their children was noted and coded. The children were then (at nearly four years) tested on their understanding of the cardinal principle.

The study found that parents’ number talk involving counting or labeling sets of visible objects related to children’s later cardinal-number knowledge, whereas other types of parent number talk were not. Talk of larger sets, containing more than 3 objects, was particularly important. This is probably because children can recognize number sets of three or less in a holistic way.