# Westminster Challenge Mental Test

Westminter School has been the toppest school in the UK for years. Their 11+ entry exams aim to sellect the best from the applicants. Now let's analyse some of the questions.

These mental calculation questions really test a boy's arithmetic skills. Those skills actually should be mastered at the early age, since the logic behind them is not complicated.

1. $11\times16=$? Some parents doubt the meaning of memorising the multiplication table beyond $9\times9$, now you see an example. Even you didn't memorise the extended multiplication table, this question is very easy to calculate: $16\times11=16\times(10+1)=160+16=176$. There're also other methods which can do the calculation in the head. Calculation time? $10$ seconds maximum.

2. $132-54=$? Different ways to do: $132-54=132-(50+4)=132-50-4=82-4=78$.

3. $35\times40\%=$? One way to solve this in head: $35\times40\%=35\times0.4=35\div10\times4=35\div5\times2=7\times2=14$.

4. $\frac{2}{3}+\frac{5}{6}=$? Find the common denominator first: $\frac{2}{3}+\frac{5}{6}=\frac{4}{6}+\frac{5}{6}=\frac{9}{6}=\frac{3}{2}$.

5. $6^2\div12^2=$? You need to know some rules first: $6^2\div12^2=(6\div12)^2=(\frac{1}{2})^2=\frac{1}{4}$.

Something you can learn from these questions: think before starting to calculate; simplify the question as much as you can.