confused 7 year old

Its a pair of scissors... :) Shes little...she will surely figure out someday... :)

The word 'scissors' comes from the French 'sciseaux' (which is also plural) which, in turn, came from the Latin and is related to the word 'excise' (meaning 'to cut something out or away'. Originally, the most common cutting instrument was a knife with a single blade, which one might call 'an excisor' - a tool for cutting something away from or off something else. Later on someone had the bright idea of making two knives work together against each other, so, naturally, as there are two blades, they were called 'excisors' or 'scissors'. Now, of course, the two blades are joined together and seem to be one 'thing'. The same has happened with the words 'trouser', 'pant', 'knicker' and so on because they are two leg coverings joined together and so are always thought of as [a pair of] trousers/pants/knickers &c.