Table 4.

Hierarchical regression models predicting arithmetic ability (simple and complex subtraction) from age, gender, general cognitive ability, symbolic, and non-symbolic magnitude processing in congenital and acquired group.

	Simple subtraction β				Complex subtraction β
	Step 1	Step2	Step3	Step4	Step 1	Step2	Step3	Step4
Congenital group
Age (months)	0.252	0.184	0.132	0.066	0.348*	0.297	0.234	0.173
Gender	−0.064	−0.096	−0.068	−0.093	−0.138	−0.154	−0.128	−0.141
Non-verbal IQ	—	0.136	0.079	0.081	—	0.117	0.070	0.077
Ps. (ACC)	—	0.176	0.120	0.084	—	0.173	0.130	0.115
Ps. (RT)	—	−0.147	−0.066	−0.105	—	−0.089	−0.003	−0.037
Reading Com.	—	0.333*	0.334*	0.292	—	0.164	0.164	0.118
Symbolic (ACC)	—	—	0.142	0.147	—	—	0.101	0.080
Symbolic (RT)	—	—	−0.210	−0.139	—	—	−0.247	−0.181
Non-symbolic (ACC)	—	—	—	0.229	—	—	—	0.197
Non-symbolic (RT)	—	—	—	−0.157	—	—	—	−0.073
	R2 = 0.068	R2 = 0.341*	R2 = 0.388	R2 = 0.401	R2 = 0.141*	R2 = 0.259	R2 = 0.312	R2 = 0.325
	(ΔR2 = 0.273*)(ΔR2 = 0.047)(ΔR2 = 0.013)				(ΔR2 = 0.118)(ΔR2 = 0.053)(ΔR2 = 0.012)
Acquired group
Age (months)	−0.117	−0.103	−0.216	−0.198	0.219	0.176	0.103	0.141
Gender	−0.198	−0.167	0.016	0.071	−0.077	−0.025	0.078	0.218
Non-verbal IQ	—	0.101	0.027	−0.005	—	0.207	0.178	0.111
Ps. (ACC)	—	0.028	−0.059	−0.062	—	−0.256	−0.303	−0.356*
Ps. (RT)	—	−0.170	−0.020	0.026	—	−0.177	−0.077	0.005
Reading Com.	—	0.389*	0.330*	0.310*	—	0.238	0.205	0.147
Symbolic (ACC)	—	—	0.428*	0.390*	—	—	0.201	0.157
Symbolic (RT)	—	—	−0.307*	−0.283	—	—	−0.218	−0.298
Non-symbolic (ACC)	—	—	—	0.209	—	—	—	0.277
Non-symbolic (RT)	—	—	—	0.022	—	—	—	0.279
	R2 = 0.058	R2 = 0.337*	R2 = 0.526*	R2 = 0.558	R2 = 0.050	R2 = 0.246*	R2 = 0.304	R2 = 0.477*
	(ΔR2 = 0.279*)(ΔR2 = 0.189*)(ΔR2 = 0.032)				(ΔR2 = 0.196*)(ΔR2 = 0.058)(ΔR2 = 0.173*)

^*p < 0.05,

Bonferroni-corrected. Ps., Processing speed; Reading Com., Reading comprehension; ACC, accuracy; RT, reaction time.