WASSCE Core Mathematics · Paper 1 style

Indices

One sample question with the full working. 12 more in the app, with instant feedback and repair sessions for the traps below.

Simplify 2³ × 2⁴.

Show the answer and working

Answer: D

Same base, multiply → add the powers: 2³⁺⁴ = 2⁷ (= 128). The base stays 2.

Trap A Multiplies the bases: The base never changes when you use index laws — only the power does. 2³ × 2⁴ is 2 × 2 × 2 × 2 × 2 × 2 × 2 = 2⁷.

Trap B Multiplies the bases: The base never changes when you use index laws — only the power does. 2³ × 2⁴ is 2 × 2 × 2 × 2 × 2 × 2 × 2 = 2⁷.

Trap C Mixes up the laws of indices: aᵐ × aⁿ = aᵐ⁺ⁿ, aᵐ ÷ aⁿ = aᵐ⁻ⁿ, (aᵐ)ⁿ = aᵐⁿ. Check with small numbers: 2² × 2³ = 4 × 8 = 32 = 2⁵.

Multiplies the bases
The base never changes when you use index laws — only the power does. 2³ × 2⁴ is 2 × 2 × 2 × 2 × 2 × 2 × 2 = 2⁷.
Mixes up the laws of indices
aᵐ × aⁿ = aᵐ⁺ⁿ, aᵐ ÷ aⁿ = aᵐ⁻ⁿ, (aᵐ)ⁿ = aᵐⁿ. Check with small numbers: 2² × 2³ = 4 × 8 = 32 = 2⁵.
Uses the wrong operation
Write the rule in words first (bearing back = bearing ± 180°; IQR = Q₃ − Q₁), then substitute. Estimate: does the size of the answer make sense?
Applies the rule for a different situation
Identify the situation first (angle at centre? opposite angles of a cyclic quadrilateral? reverse bearing?) and write the rule that belongs to it before calculating.
Sign slip when moving or multiplying terms
Moving a term across "=" means doing the opposite operation to BOTH sides. And (−)×(−) = (+). Write each step on a new line; circle every minus sign before you expand.