$12\times6=$  

(a)  

 $18\times2-24=$  

(a)  

 $\frac{3}{4}+\frac{4}{8}=$  

(a)  

 $Convierte\ \frac{2}{5}\ a\ decimal$  

(a)  

 $\frac{2}{3}\times\frac{3}{5}=$  

(a)  

 $115.4-12.4=$  

(a)  

(a)  

 $9^2=$  

(a)  

 $0.5+\frac{2}{4}-\frac{1}{3}=$  

(a)