Table 1. Behavioral results from the abacus expert performing the mental addition tasks (8-digit and 4-digit addition), as well as the average subjects performing the mental addition tasks (2-digit and 1-digit addition).

Average subjects	Task	V-2	V-1	A-2	A-1
	AR (%)	77.0±2.5	98.0±0.6	66.3±3.8	96.3±0.9
	RT (s)	1.95±0.14	1.12±0.07	2.30±0.18	1.32±0.14
Abacus expert	Task	V-8	V-4	A-8	A-4
	AR (%)	100	100	100	100
	RT (s)	1.86±0.69	1.65±0.81	2.41±0.91	1.76±0.73