Read the word on the card.
Change the sound.
Say what the new word will be
Check yourself on the back of the card.

at
change the ending sound to /m/

at
add a /c/ to the beginning

cat
change the middle sound to /o/

cot
change the beginning sound to /d/

dot
change the beginning sound to /g/

tad
change the beginning sound to /d/

dad
change the beginning sound to /m/

mad
change middle sound to /i/

mid
change beginning sound to /d/

did
change ending sound to /g/