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• What is this question used for?
• What does this question assess?
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### History and Feedback

#### Checkpoint description

Describe what's changed since the last checkpoint.

#### Christian Lawson-Perfect8 months, 1 week ago

Saved a checkpoint:

Replaced some javascript with pattern restrictions. There are still some string restrictions that could be replaced with pattern restrictions.

Published this.

#### Christian Lawson-Perfect2 years, 6 months ago

Gave some feedback: Ready to use

#### Christian Lawson-Perfect2 years, 6 months ago

Saved a checkpoint:

I changed the denominators for parts f,g and h from number entry to mathematical expression. While the answer is always a number, a student who's misunderstood might want to write a surd. You should let them fail!

I don't know why each line of the derivations ended with a comma, but this isn't conventional.

With those things fixed, this is a good question.

#### Elliott Fletcher2 years, 7 months ago

Gave some feedback: Needs to be tested

#### Lauren Richards2 years, 7 months ago

Gave some feedback: Has some problems

#### Lauren Richards2 years, 7 months ago

• MAIN PARTS
• Part a) should have more numbers rather than just two.
• I think you will have a problem with people not knowing how to insert a square root sign into their answers, meaning they will be scuppered for all of the questions. I think you will need to tell them how to in the parts by giving an example. Say like "3\sqrt{5} can be written as 3*sqrt(5)". Alternatively, you could set it up via gap fill so that all of the answers can be given in a pre-prepared square root sign.
• Part b)'s steps could be a little off-putting for someone. They only need the first rule to do part b) but you have given them an extra rule that isn't relevant. It might confuse them.
• You don't need colons after "Simplify" in each part.
• Part h), your model answer included an unsimplified numerator, which might not be what the user gives. You didn't multiply out 3(\sqrt{3}+18) but writing 3\sqrt{13}+54 is not wrong.
• ADVICE
• I think you should restate the question in part a) after stating the rule and before the actual advice for part a).
• The examples listed for part a) and b) were not the ones I was asked in the test run. It was talking about \sqrt{405} both times when I had been asked about \sqrt{1377} in part a) and \sqrt{1053} in part b).
• In part c), I think you should show how the fraction cancels down a bit more by stating that the two \sqrt{17} cancel on the numerator and denominator. Someone might get lost if they followed the first method.

#### Elliott Fletcher2 years, 7 months ago

Thanks for your feedback, i have corrected the mistakes

#### Elliott Fletcher2 years, 7 months ago

Gave some feedback: Needs to be tested

#### Chris Graham2 years, 7 months ago

Rather than having "Answer:" before the gap, I think I'd rather that the surd was repeated, e.g. "$\frac{1}{\sqrt{11}}=$"

In (g) and (h) your answers are displayed with a decimal on the numerator, which I presume is not what you intended. The reason for this is that the braces evaluate {{n}-sqrt({a})} to a decimal number. Try this instead to retain the integer values of n and a:

({n}-sqrt({a}))/{{n}^2-{a}}.

Good work with the advice, which is well laid out and punctuated.

#### Chris Graham2 years, 7 months ago

Gave some feedback: Has some problems

#### Elliott Fletcher2 years, 7 months ago

Gave some feedback: Needs to be tested

#### Elliott Fletcher2 years, 7 months ago

Created this.
Name Status Author Last Modified
Using Surds, Rationalising the Denominator Ready to use Elliott Fletcher 20/11/2019 14:44
Katherine's copy of Using Surds, Rationalising the Denominator draft Katherine Tomlinson 31/07/2017 11:50
Using Surds, Rationalising the Denominator draft Adrian Jannetta 25/09/2017 16:30
Harry's copy of Using Surds, Rationalising the Denominator draft Harry Flynn 18/11/2018 12:39
Surds Rationalisation draft Johnny Yi 24/01/2019 04:29
Surds Rationalisation (Diagnostic Test) draft Johnny Yi 24/01/2019 04:30
Simon's copy of Using Surds, Rationalising the Denominator draft Simon Thomas 06/06/2019 09:40
John's copy of Using Surds, Rationalising the Denominator draft John Wick 17/06/2019 11:00
John's copy of John's copy of John's copy of John's copy of John's copy of John's copy of John's copy of John's copy of John's copy of John's copy of John's Using Surds, Rationalising the Denominator draft John Wick 10/07/2019 16:00
Katy's copy of Using Surds, Rationalising the Denominator Ready to use Katy Dobson 20/09/2019 15:10
Paul's copy of Using Surds, Rationalising the Denominator draft Paul Verheyen 01/10/2019 16:48
Ann's copy of Using Surds, Rationalising the Denominator draft Ann Smith 20/01/2020 14:08

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(a number)

Numbers between and (inclusive) with step size
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(text string)

(numbers)

(text strings)

This variable is an HTML node. HTML nodes can not be relied upon to work correctly when resuming a session - for example, attached event callbacks will be lost, and mathematical notation will likely also break.

If this causes problems, try to create HTML nodes where you use them in content areas, instead of storing them in variables.

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