Writing out numbers on a check should be pretty straight forward.
Here's a list of the numbers you may need when filling out the cheque.
One = 1
Two = 2
Three = 3
Four = 4
Five = 5
Six = 6
Seven = 7
Eight = 8
Nine = 9
Ten = 10
Eleven = 11
Twelve = 12
Thirteen = 13
Fourteen = 14
Fifteen = 15
Sixteen = 16
Seventeen = 17
Eighteen = 18
Nineteen = 19
Twenty = 20
Twenty one = 21
You'll then need the major denominations:
Hundred = 100
Thousand = 1000
Million = 1000000
You may also need to learn the various denominations for the currency you are using (i.e. $ = dollars and ¢ = cents)
Here's a useful clip on how to write a cheque that you might want to watch too:
