The word '' FOIL '' was originally intended solely as a mnemonic for high - school students learning algebra , but many students and educators in the United States now use the word '' foil '' as a verb meaning '' to expand the product of two binomials '' .
The word '' FOIL '' was originally intended solely as a mnemonic for high - school students learning algebra . 
 Many students and educators in the United States now use the word '' foil '' as a verb meaning '' to expand the product of two binomials '' .