Table 1:

Variable List

Variable type	Variable List
Demographics	Age at pretest, Sex (1=male), Free or reduced price lunch, Special education, Race and ethnicity, English Learner status
Pretests: General Processing	Nonverbal Reasoning, Processing Speed, WM-Listening Recall, WM-Counting Recall, Attentive Behavior, Listening Comprehension
Pretest: Reading	WRAT-Reading
Mathematics: First-Grade Content (only collected in fall and spring of First-Grade)	Arithmetic Combinations, Double-Digit Calculation, Story Problems
Mathematics: First-Grade Content (collected at every wave)	Facts Correctly Retrieved, Number Sets
Mathematics: Cross-Grade Content (collected at every wave)	WRAT-Arithmetic, Number Line, KeyMath-Numeration

Note: For details about scoring, see Supplementary Materials. For variable means by group at all waves, see Tables S1 and S2