. Author manuscript; available in PMC: 2022 Jun 9.

Published in final edited form as: Child Dev. 2022 Jan 13;93(3):778–793. doi: 10.1111/cdev.13724

TABLE 1.

Means (SDs) on place value measures in kindergarten and first grade

	Kindergarten (n = 279)		First grade (n = 231)
Assessment	Mean number correct (SD)	Mean proportion correct (SD)	Mean number correct (SD)	Mean proportion correct (SD)
Magnitude comparison	19.07 (4.03)	.53 (.32)	22.67 (2.92)	.81 (.23)
Number line estimation	82.09 (8.75)	.82 (.09)	88.65 (7.44)	.89 (.07)
Transcoding	6.43 (3.08)	.54 (.26)	9.42 (2.89)	.78 (.24)
Base-10 counting	3.71 (2.77)	.37 (.28)	6.40 (2.68)	.64 (.27)
Which number has __?	4.60 (1.17)	.65 (.29)	5.01 (1.27)	.75 (.32)
Expanded notation	3.01 (1.78)	.25 (.45)	4.81 (1.48)	.70 (.37)

Note: Mean proportion correct scores of expanded notation, Which number has __?, and magnitude comparison are adjusted for forced-choice responding. The mean number correct for number line estimation was derived from the percent absolute error (PAE) score by subtracting the PAE from 100. The mean proportion correct score for number line estimation was derived by dividing this reversed PAE score by 100.