
Control

DD


Simple operations (RT)

61 sec

123 sec**

Addition

1.35%

4%

Subtraction

0%

5%

Multiplication

2.5%

4.5%

Division

5%

8.5%

Horizontal operations (RT)

13 sec

21 sec**

Addition

6%

17.5%

Subtraction

23%

23%

Multiplication

6%

15%

Division

2%

17%*

Vertical operations (RT)

625 sec

822 sec

Addition

5%

18%**

Subtraction

13%

32%**

Multiplication

26%

23%

Division

25%

42%

Decimals (RT)

238 sec

294 sec

Addition

12%

16%

Subtraction

28%

58%**

Multiplication

31%

70%*

Fraction (RT)

547 sec

658 sec*

Addition

13%

28%

Subtraction

9%

25%*

Multiplication

9%

21%

Division

5%

14%

 Note. An asterisk indicates a significant difference between the performances of the developmental dyscalculia group and the control group. * p < 0.05, ** p < 0.01.