#2.3A
understand that a letter may represent an unknown number or a variable
#2.3B
use correct notational conventions for algebraic expressions and formulae
#2.3C
substitute positive and negative integers, decimals and fractions for words and letters in expressions and formulae
Evaluate \(2x - 3y\) when \(x = 4\) and \(y= -5\)
#2.3D
use formulae from mathematics and other real-life contexts expressed initially in words or diagrammatic form and convert to letters and symbols
#2.3E
derive a formula or expression
#2.3F
change the subject of a formula where the subject appears once
Make \(r\) the subject of \(A = \pi r^2\)
Make \(t\) the subject of \(v = u + at\)
#2.3G
understand the process of manipulating formulae or equations to change the subject, to include cases where the subject may appear twice or a power of the subject occurs
Make \(r\) the subject of \(~V = \dfrac{4}{3} \pi r^3\)
Make \(a\) the subject of \(~3a + 5 = \dfrac{4-a}{r}\)
Make \(l\) the subject of \(~T = 2\pi\sqrt{\dfrac{l}{g}}\)