'Number line' affects child's memory

The University of Oklahoma study suggested that the way kids visualise numbers reflects their understanding of what the symbols mean. When children in Western cultures first learn numbers, they place them on number lines from left to right. But the placement is uneven: smaller numbers are spaced farther apart than larger numbers, which are crunched up toward the end of the line.

Gradually, this placement evens out, corresponding with the child’s understanding of what the numbers mean, said Clarissa Thompson, co-author of the study. “Young children’s knowledge sometimes seems impressive, because they can count, ‘one, two, three, four, five, six, seven, eight, nine, ten,’ but often they just learn by rote,” Thompson said.

To find out how number-line visualisation relates to understanding of numbers, the researchers gave a group of children a stack of blank number lines with “0” written on the left end and “20” on the right end. Each child heard a series of numbers from one through 19 and had to mark on the number line where they thought that number belonged.

Next, the children were told a story that included a few numbers. Children with a more linear number line were better at remembering the numbers.