UC Santa Barbara

This paper examined the number magnitude understanding and estimation of elementary

students. Children as early as kindergartner differ in their understanding of numerical

magnitudes. Research has found that teaching linearity of numbers was effective in

improving children’s estimation of numerical magnitudes (Booth & Siegler, 2008).

Extending this line of work, I examined two different ways that linearity of numbers is

taught: multiple 10 blocks and bundles. There were 58 kindergarten and first-grader students

from Southern California randomly assigned to one of the three instructional contexts:

blocks, bundles and control condition. I found that the students using the

combination of base-10 and unit blocks gained more from the instruction than the other

two groups. The students in the blocks group presented linearity for mental number line after the instruction. However, those in bundle and control groups could not.