Table 1.

Means (Standard Deviations) and Ranges of Assessments Used in Study 1 (N = 152)

Assessment point and task	M (SD)	Range
Beginning-of-year scores
Number line knowledge (0–1,000 number line linear R2)	0.55 (0.19)	0.00–0.98
Spatial skill (Thurstone mental rotation; items correct of eight)	4.62 (1.62)	0–8
Math achievement (WJ-III Applied Problems W score)	451.4 (18.1)	409.0–490.0
Reading achievement (WJ-III Letter–Word Identification W score)	437.4 (34.0)	348.0–501.0
End-of-year score
Number line knowledge (0–1,000 number line linear R2)	0.59 (0.19)	0.00–0.99

Note. WJ-III = Woodcock-Johnson III Tests of Achievement.