Whole Numbers

 

Whole number operations can be written in the expanded form. The expanded form will show you how the place value works. Place value becomes very important when we have to regroup, or borrow numbers.

Demonstration:

  • Addition

    Eg: 143 can be written as 100 + 40 + 3 , 254 can be written as  200 + 50 + 4. then their sum can be calculated as:

                143 + 254 =            100 + 40 + 3                                                        
                                             + 200 + 50 + 4                                                     
                                                300 + 90 + 7 = 397 

  • Subtraction

               628 - 325  = ?        600 + 20 + 8                                                
                                             - 300 + 20 + 5                                              
                                               300 + 0 + 3 =    303   

  • Multiplication by multiples of ten

           5 x80 = 5 x 8 tens    = 40 tens = 400
           5 x80 = 400