Add a beginning consonant sound to the ending ig to read the three-sound words big, pig, and dig.
New ending this week: ig. Add b to the front: big. Add p to the front: pig. Add d to the front: dig. Same trick as cat, sat, and mat, brand new ending.
Once you know one ending like ig, you can build many words from it just by swapping the very first sound.
Mastery looks like: They read big, pig, and dig by blending a beginning sound onto the known ending ig, in any order, without hints.
Common stumbles: Reading the ending correctly but guessing at the beginning sound instead of blending it; mixing up the ig ending with the earlier at ending.