4568 + 7890

(a)  

4567 + 4531 =

(a)  

5673 - 1234 =

(a)  

8903 - 4531 =

(a)  

5672 - 2345 =

(a)  

456 x 2 =

(a)  

753 x 3 =

(a)  

123 x 4 =

(a)  

 $3\sqrt{669}$   

(a)  

 $5\sqrt{155}$  

(a)  

 $2\sqrt{842}$  

(a)