By writing each number correct to 1 significant figure, estimate the value of \(\frac{39 \times 21}{4.1}\).

By writing each number correct to 1 significant figure, estimate the value of \(\dfrac{412 + 189}{29}\).

Solve the equation \(\frac{m}{4} = 9\) to find the value of \(m\).

Simplify \(2x^{3}y \times 4x^{2}y^{5}\).

Find the equation of the straight line that is parallel to \(y = 4x - 1\) and passes through the point \((0,6)\).

Simplify \(4a + 7b - a + 2b\).

Write \(\frac{1}{81}\) as a power of \(3\).

There are \(30\) students in a class and \(18\) of them are girls. Work out the percentage of the class that are girls.

Write \(45\%\) as a fraction in its lowest terms.