From any addition fact such as
1462 + 3763 = 5225
we can work out two subtraction facts.
Here we get
5225  1462 = 3763
and
5225  3763 = 1462
This is handy because we can use additions to check subtractions.
Example 1
Caleb says that
5681  1724 = 

Use addition to check if he is right or wrong.
Answer
Add:
So 3957 + 1724 = 5681
Caleb is right.
Example 2
Dahlia says that
6286  2457 = 

Use addition to check if she is right or wrong.
Answer
Add:
So 4829 + 2457 = 7286 not 6286
Dahlia is wrong.
Want to understand this further and learn how this links to other topics in maths?
Why not watch this video?