Addition by Partitioning




Worked Examples of Addition by Partitioning

Click here to return to Mental Arithmetic homepage.

In Years 3/4 children start to lay out numbers to be added vertically, to get ready for the introduction of column addition typically in Years 5/6.
When two-digit numbers are to be added, children are usually taught to add the tens first which gives a rough answer, and then add the units and add those to the total of the tens.
For three-digit numbers, the hundreds are added first, then the tens, and then the units.


Vertical Addition by Partition with 2-digit Numbers

  57
+ 83
 130  (50 + 80) Add the tens
  10  (7 + 3)   Add the units
 140



Vertical Addition by Partition with 3-digit Numbers

  215
+ 328
  500  (200 + 300) Add the hundreds
   30  (10 + 20)  Add the tens
   13  (5 + 8)    Add the units
  543


Press F5 or click here to see more examples of addition by partitioning.

Buy mental maths workbooks for children - books for sale


All worksheets published online at Mental-Arithmetic.co.uk are free to print without modification
for non-commercial use by schools, children, parents, and care givers.
2010-2018 Mental-Arithmetic.co.uk - All Rights Reserved