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   59 + 70  120  (50 + 70) Add the tens    9  (9 + 0)   Add the units  129 Vertical Addition by Partition with 3-digit Numbers   326 + 797  1000  (300 + 700) Add the hundreds   110  (20 + 90)  Add the tens    13  (6 + 7)    Add the units  1123

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



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.
© 2010-2021 Mental-Arithmetic.co.uk - All Rights Reserved