- 
                  
Math
 - 
                  
Duration of time
 - 
                  
Age 5-7
 - 
                    
level: Grade-1
 - 
                  
English
 
Author's Instructions
how to calculate time duration
- 
                  
Math
 - 
                  
Duration of time
 - 
                    
Age 5-7
 - 
                    
level: Grade-1
 - 
                  
English
 
Author's Instructions
how to calculate time duration