Chris Graham

Chris Graham commented on Identify independent events 8 years, 5 months ago

I'm not sure there's any reason to have "Must the fraction be reduced" ticked. I can't think of a reason why the student might enter any other equivalent fraction. I would untick to remove the prompt, which could unnecessarily confuse a student.

The following statement,

"Randomly selecting a boy from a class of 15 boys and 15 girls given that the previous randomly selected student from the class was a girl"

is ambiguous and needs to be worded differently. Has the girl been removed from the class? Without that information, it is impossible to answer.

To some extent, the same is true of the card deck question, which could also be clearer. 

Chris Graham on Identify independent events 8 years, 5 months ago

Gave some feedback: Has some problems

Chris Graham on Find the equation of a line through two points - negative gradient 8 years, 5 months ago

Gave some feedback: Has some problems

Chris Graham commented on Find the equation of a line through two points - negative gradient 8 years, 5 months ago

Much better! 

One more thing... points A and B should be labelled the other way round. Let's give your question the context of driving in a car: if you travel from A to B then, as it stands, the gradient is positive. Related to this, you do not give any indication where the equation for the gradient comes from. You could say something like, the gradient is the ratio of the vertical change ($y2-y1$) to the horizontal change ($x2-x1$).

Chris Graham commented on Create an algebraic expression from a word problem, simplify, and evaluate 8 years, 5 months ago

Looks good. You still talk about single sweets in part (c) and in the advice, so you'll need to change to packets there too.

Chris Graham commented on Weight of a scoop in two ice cream parlours 8 years, 5 months ago

Good question. Just a couple of things:

In the statement you say that the shops will be referred to as $s$ and $t$, but this notation is not used in the question itself, just the advice, so why not introduce this shorthand at the start of the advice instead.

In your advice, you have several calculations involving fractions inside the align environment. This is fine, however you will notice that they appear quite squashed with the default line spacing. You could add [1pt] (play around with the number) immediately after the line-break (the \\) to add additional line spacing, e.g.

\overline{s} &= \frac{\sum s}{n} \\[2pt]
...

Chris Graham on Weight of a scoop in two ice cream parlours 8 years, 5 months ago

Gave some feedback: Has some problems

Chris Graham commented on Find the equation of a line through two points - negative gradient 8 years, 5 months ago

Brad, why not split this into two parts, the first asking for the gradient and intercept and the second the equation. The student can then see if they are on the right lines. You could also then use adaptive marking (ro replace m and c) in the second part.

Chris Graham on Create an algebraic expression from a word problem, simplify, and evaluate 8 years, 5 months ago

Gave some feedback: Has some problems

Chris Graham commented on Create an algebraic expression from a word problem, simplify, and evaluate 8 years, 5 months ago

Why only one part? There doesn't seem to be any good reason why it shouldn't be in two parts.

£2 for a lollipop?! They are unreasonably expensive sweets. May need a re-think to make this more realistic. You state Jerry eats a lot and I would disagree (based on my own sweet-eating habits), so perhaps these could be packets of sweets?

You have mixed singular "Jerry", and plural "they".

A good addition would be to add a step to (what will be) part a) which asks for an expression for each of the 3 components. This bit should also be above the cost equation in the advice. "we can see that the unsimplified expression..." can't be seen at all, until those steps have been taken.