Each question is a number raised to a power: 7² = ?, 4³ = ?. Squares go up to 20 and cubes to 12, which is as far as the arithmetic is worth doing by hand - 20³ is 8,000, and writing that out teaches multiplication rather than exponents.
These sheets stay at squares and cubes. That is what sixth to eighth grade uses, and a fourth power is a calculator exercise rather than something to practise. Our order of operations worksheets put squares and cubes inside longer expressions once evaluating them on their own is automatic.
How many times to multiply a number by itself. 4³ is 4 × 4 × 4, which is 64. The small raised number is the count, not something to multiply by.
4 × 3 is 12; 4³ is 64. It is the most common mistake with exponents, and it is why these sheets ask for the value rather than for the expanded form.
Because those are the powers that come up in real work - area is a square, volume is a cube - and because anything higher is a calculator exercise. They are also the two that print properly on a worksheet.
Sixth grade introduces them, and they are used from then on in order of operations, area and volume, and eventually in scientific notation.