More mental addition
Adding two 3-digit numbers mentally. Often it is best to start with the hundreds, then the tens and finally the units; this is the opposite order than when using written methods.
            
          5 pages
        
            
        More mental addition
Adding two 3-digit numbers mentally. Often it is best to start with the hundreds, then the tens and finally the units; this is the opposite order than when using written methods.
 
                     
                                     
                                     
                                     
                                    