ffirs.indd

Addition 115
If the above fi gures were amounts of money with a decimal, it would
make no diff erence. You can use this method to check almost all
of your additions, subtractions, multiplications and divisions. And
you can have fun doing it.
Note to parents and teachers
The basic number facts are quickly learned when children
master these techniques and learn the multiplication
tables.
Casting out nines to check answers will give plenty of
practice with the combinations of numbers that add to 9.
These exercises don’t need to be drilled. They are learned
naturally when students use these strategies.
Once a student knows the basic makeup of numbers, he
or she can easily add small numbers without mistakes
and without borrowing.