Vicky Hall

In part c), you have mixed up the values of $r$ and $h$ in the solution. I would also change the possible values of $r$ and $h$ so that $h$ is always greater than $r$, because the diagram makes it look as though this is the case.

Link the formulae you are stating to the questions you are asking. For example, in part a), reword the question to say: 'Calculate the area of the frisbee given that the area of a circle is $\mathrm{Area}=\pi r^2$. Part d) needs to be reworded as the current prompt doesn't make sense and has 'cm' randomly placed in the sentence.

Remember full stops at the end of all sentences and at the end of the statement. If the formula is the end of your question, put the full stop after that. 

In the advice section there are issues with a few of the solutions. In part a), the penultimate line of working is correct but the final line gives a totally different number. In part c), $r$ and $h$ are mixed up like they were in the expected answer to the question. And in part d), the solution isn't rounded in the final line of working, as you've done in all of the other sections. 

Question bii) asked me to factorise $x^2+4$ and the solution came up as $(x+2)(x-2)$. This needs to be fixed so that either the answer is 'has no real solutions and cannot be factorised' or the expression is $x^2-4$ instead.

Also, I would reword the question for b). There's no need for the student to complete the square for any of the expressions so I would just change it to say 'factorise the following expressions'.