Table 2.

Regression Models Predicting Individual Differences in First-Grade Number Combination Skill

Model	R²	SEE	R² Change	F Change	p-value	B	SE	Beta	t	p-value
1: Numerosity	.656	7.16	.656	(2,202) 192.75	< .001
Constant						27.03	1.73		15.66	< .001
Number Line Estimation						−0.31	0.07	−.20	− 4.21	< .001
Number Sets Test						7.06	0.47	.70	15.02	< .001
2. Numerosity + Domain-General	.677	7.08	.021	(8,194) 1.56	.141
Constant						14.64	6.03		2.43	.016
Language						0.43	0.69	.04	0.62	.535
Attentive Behavior						0.11	0.05	.12	2.18	.031
Central Executive						−0.41	0.04	−.06	−1.03	.305
Phonological Loop						0.04	0.03	.05	1.06	.290
Visuospatial Sketchpad						0.03	0.04	.04	0.74	.459
Concept Formation						0.03	0.05	.03	0.53	.594
Nonverbal Reasoning						−0.03	0.07	−.02	−0.37	.712
Processing Speed						0.03	0.04	.04	0.85	.394
Number Line Estimation						−0.27	0.08	−.17	−3.46	.001
Number Sets Test						6.11	0.59	.61	10.37	< .001