CALCULATING • PARTITIONING FOR ADDITION 83

(^80) + 54

Partitioning for

addition

Adding numbers is often easier if you split them into numbers

that are easier to work with and then add them up in stages.

This is called partitioning. There are a few different ways to do it.

Let’s add 80 and 54.

80 is already a multiple of 10, but we can

break 54 into two parts like this: 50 + 4

Now we can add 50 to 80 to make 130.

Now we just add 4 to 130 to

give the answer 134.

(^80) + 50 4
(^1304)
134

• =


• 
  

  =

  
  

  47 + 35 = 82
  We start by adding the tens together
  and writing the answer to the right of
  the equals sign: 40 + 30 = 70
  And next, we add the ones together: 7 + 5 = 12
  By partitioning the numbers, we’ve found
  that 47 + 35 = 82
  Now it’s easy to recombine our two
  answers to get the total: 70 + 12 = 82
  Let’s add 47 and 35.
  To help with the tricky numbers, we can
  put the numbers on a grid and label the
  columns to show their place values.
  47 + 35 =?
  Partitioning using
  multiples of 10
  Another way to partition
  is to split just one
  number, so it’s easier
  to add on. It often helps
  to split one number into
  a multiple of 10 and
  another number.
  Recombine the tens
  and ones to find the total^82
  40 30 70
  7 5 12

  
  


• 
  


• 
  

  =

  
  

  T O
  47 35 ??
  T O T O

  
  


• =
  T O T O
  T O
  T O
  Partitioning means
  breaking numbers down
  then adding them
  together in stages.
  T O
  T O T O
  082_083_Addition_facts_Partitioning_for_addition.indd 83 29/02/2016 18:02