This is a cheap and simple way to practice plurals with students: write the noun on the sentence strip, fold the right hand corner to cover up whatever gets taken away on the reform of the word, then write the new ending that makes the word plural.
FREE! ~ This grammar mini lesson pack covers nouns, singular and plural nouns, the verb “be”, pronouns, adjectives, and adverbs. This is a sample taken from my grammar bundle. The complete grammar pack can be found at: https://www.teacherspayteachers.com/Product/Grammar-2118159