Mammoth Memory

Addition

Traditional method or column addition

Requires you to understand that the number such as `385` is in fact three 100’s eight 10’s and five 1’s.

Or           `300 + 80 + 5`

And this place value system is called the decimal system.

A decimal number can be broken down into hundreds, tens, units, hundredths and thousandths 

Remember this is better than adding pounds shillings and pence.

Example of the column method of addition

NOTE:

`d` = pennies = `12` pennies in a shilling

`S` = shillings = `20` shillings in a pound

`£` = Pound = `240` pence `(12xx20=240)`

 

and `8d+7d+10d=25d` or `2` shillings and `1d`

and `4S+5S+3S` and `2S` carried over is `14` shillings

 

Example 1

`398+427`

     
`3` `9` `8`
`4` `2` `7`
`8` `2` `5`

 

Answer: `=825`

To see this example step by step

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Traditional addition

Example 1

`398+427`


  3 9 8    
`+` 4 2 7    
   

 

    1      
  3 9 8   Add the ones (8 ones `+`7 ones `=`15 ones)
`+` 4 2 7   Regroup (15 ones `=`1 ten `+`5 ones)
   
      5    

 

 

  1 1      
  3 9 8   Add the tens (1 ten `+`9 tens `+`2 tens `=`12 tens)
`+` 4 2 7   Regroup (12 tens `=`1 hundred `+`2 tens)
   
    2 5    

 

  1 1      
  3 9 8   Add the hundreds (1 hundred `+`3 hundred `+`4 hundred `=`8 hundred)
`+` 4 2 7  
   
  8 2 5    

 

Answer: `=825`

 

 

 

Example 2

`365+297`

     
`3` `6` `5`
`2` `9` `7`
`6` `6` `2`

 

Answer: `=662`

To see this example step by step

Press Here

Traditional addition

Example 2

`365+297`

  3 6 5    
`+` 2 9 7    
   

 

    1      
  3 6 5   Add the ones (5 ones `+`7 ones `=`12 ones)
`+` 2 9 7   Regroup (12 ones `=`1 ten `+`2 ones)
   
      2    

  

  1 1      
  3 6 5   Add the tens (1 ten `+`6 tens `+`9 tens `=`16 tens)
`+` 2 9 7   Regroup (16 tens `=`1 hundred `+`6 tens)
   
    6 2    

 

  1 1      
  3 6 5   Add the hundreds (1 hundred `+`3 hundred `+`2 hundred `=`6 hundred)
`+` 2 9 7  
   
  6 6 2    

 

Answer: `=662`

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