A component of literacy development and reading instruction for young children involves the ability to break words into smaller units. This skill falls under the umbrella of phonological awareness which is a broad term encompassing phonemes, rhymes, words, syllables and onsets and rimes.
An onset is the the initial consonant(s) sound of a syllable (the onset in the word cat is c-; of string, str-). A rime is the part of a syllable from the first vowel onwards (the rime of cat is -at; of string, -ing).
In my first grade class I created a game for my students to deepen their understanding of onsets and rimes while having a bit of fun.
I made cards for each of the 49 common onsets and 37 common rimes, and gathered an hourglass timer, a spinner and some paper. Students, working in teams or individually, spin to see if they will pick an onset card or a rime card. Once a card is chosen, the timer is set and students write down as many words as they can that start with the selected onset (ch-, d-, etc.) or end with the rime shown on the card (-at, -ake, etc.).
It can also be adjusted depending on students age and ability. In kindergarten I generally include only onsets with one letter and simple rimes such as -at, -an, -it. In first grade onsets include digraphs and blends while rimes include vowel teams and silent /e/ syllable types.
I have included a sample student sheet (click to embiggen) but it works just as well for students to use a blank piece of paper once they understand the task.