Challenge Group I (13 yo above Abacus)

 $7,431\times906=$  

(a)  

 $548\times1,523=$  

(a)  

 $2,010\times398=$  

(a)  

 $65,797\times49=$  

(a)  

 $863\times2,704=$  

(a)  

 $9,054\times587=$  

(a)  

 $379\times8,345=$  

(a)  

 $15\times71,926=$  

(a)  

 $4,862\times612=$  

(a)  

 $236\times8,001=$  

(a)