Christian Lawson-Perfect

Christian Lawson-Perfect on Surds simplification 8 years, 6 months ago

Saved a checkpoint:

I've reworded the statement slightly.

Christian Lawson-Perfect on Expansion of brackets 8 years, 6 months ago

Gave some feedback: Has some problems

Christian Lawson-Perfect commented on Expansion of brackets 8 years, 6 months ago

The question statement is a bit of a run-on sentence. Try something like:

Expand each of the expressions below. 

Multiply each of the terms inside the brackets by the term outside the brackets.

One of the GCSE textbooks might have a good formulation of this prompt that you can use for inspiration.

Why have you made your own part headers instead of splitting each expression into its own part?

Think about the difficulty curve for these problems: you should start with a very simple example, and slowly add more complicated elements, one at a time. So you might start with $2(x+1)$, then follow that with $x(x+1)$, which requires multiplying $x \times x = x^2$. Think about how games do this: you begin with very simple challenges while you get used to the controls, then more elements are added in as you become more secure in those.

While randomised numbers are good, this question is about algebra so maybe restrict coefficients to single digits. I don't know my 17 times table! Don't let students fail for the wrong reason: a mental arithmetic error is a distraction here.

The advice is written in the passive voice: "Brackets are expanded by..." Give a concise explanation of what "expanding brackets" means - you multiply terms so that no brackets are left - and then give a few generic examples, such as $a(x+2) = ax + 2a$.

Christian Lawson-Perfect on Percentages and ratios - box of chocolates 8 years, 6 months ago

Gave some feedback: Has some problems

Christian Lawson-Perfect commented on Percentages and ratios - box of chocolates 8 years, 6 months ago

Statement

"There is an equal distribution of chocolates throughout the box." seems either clunky or ambiguous to me. Maybe "The box contains equal numbers of each kind of chocolate."

Parts

In part c, you want each kind as a proportion of the remaining chocolates. You could say "what percentage of the remaining chocolates are plain?"

In part d, put the i) and ii) in italic or bold to make them stand out.

In part e, I would prefer "$\Pr(\text{Nutty chocolate picked}) = $" to "Probability = ". Set precision restrictions on the gaps - 2 decimal places for the first one, and 0 decimal places for the second one.

Advice

"Whole complete" is a tautology. You could say "100% represents the whole box of chocolates".

In the advice for part b, rather than "You know that each type of chocolate is represented equally in the box, so you need to find 20% of the original number of chocolates." you could say "We worked out above that each type of chocolate makes up 20% of the box, so we need to work out 20% of {chocs}".

In part c, I'd replace the first sentence with "There are now {type} fewer chocolates in the box, leaving {chocs}-{type} = {minusc}."

Part d: NEVER use the word "simply"! No matter what you're talking about, there will always be a student for whom it isn't simple, and saying so won't make them feel great. Cutting out the word "simply" leaves a perfectly acceptable sentence. And again you've got "amount" where it should be "number". "Amount" is used for continuous measurements, while "number" is used for discrete numbers of objects.

Part e: "The amount of chocolates in the box is equal to {a}" is a clunky way of saying "There are {a} chocolates left in the box". You might want to put "(to 2 decimal places)" after the calculation.

You've got some stray bits formatted as headers instead of paragraphs.

Christian Lawson-Perfect commented on Basic arithmetic operations: addition and subtraction 8 years, 6 months ago

Did you do something to make the revealed answers for part c work? It looks OK on my PC now.

Christian Lawson-Perfect on Access the student's answer to another part in a marking script 8 years, 6 months ago

Gave some feedback: Ready to use