Variable ItemExtras`Const`

ItemExtras: readonly [
    "calculator",
    "financialCalculatorMonthlyPayment",
    "financialCalculatorTotalAmount",
    "financialCalculatorTimeToPayOff",
    "periodicTable",
    "periodicTableWithKey",
] = ...

ItemExtras represent extra UI elements that help the learner in answering the question (such as a calculator for questions where solving by hand is not material to testing understanding of the skill).