This a Moodle question type which extends the built-in 'calculated' question type. Teachers can create questions like,

How much is {apples} + {oranges}? 

— where the {wildcards} become M and N × images of apples and oranges respectively.

It is aimed at pre/primary/elementary-school students (approximately age 3-9). Currently supported wildcards — please see the Documentation link below (each wildcard may be used with or without an 's', eg. {cookies} and with an optional differentiator). For example,

 {apples_1} - {apples_2}