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Checkpoint description

Describe what's changed since the last checkpoint.

Martin Kilian 4 months ago

Gave some feedback: Ready to use

Luis Hernandez 8 months, 2 weeks ago

Gave some feedback: Has some problems

Luis Hernandez 8 months, 2 weeks ago

Gave some feedback: Ready to use

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Christian Lawson-Perfect 2 years, 1 month ago

Saved a checkpoint:

I don't think this question is worth saving. I've split part d, about finding a given term, into a separate question.

Ideally, there'd be a question combining parts a and b, asking you to sort a few sequences into linear, quadratic, geometric, or other. 

I don't think there's any point in the parts which ask you to give the next three terms of the triangle, square, and cube numbers.

Restore this checkpoint

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Christian Lawson-Perfect 2 years, 1 month ago

Gave some feedback: Should not be used

Elliott Fletcher 2 years, 1 month ago

Published this.
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Bradley Bush 2 years, 2 months ago

Gave some feedback: Needs to be tested

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Bradley Bush 2 years, 2 months ago

Thank you for the feedback Christian:

  • I have added tables to the feedback for parts and b to make the working easier to follow.
  • I have added a table to the feedback for c also to analyse the difference between terms but I have included Hannahs solution using the formula as an alternative method of solving this.
  • I have altered question d to be the more generic randomisable sequence equation which you suggested.
  • I attempted to explain the solution using a table here to find the differences too but I am not too sure how thoroughly this would explain the way you work out that the sequence is squared numbers and cubic numbers without simply recognising them. Nor am I confident I even know how to recommend solving this problem if you do not recognise the squared or cubic terms on your own?
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Christian Lawson-Perfect 2 years, 2 months ago

Gave some feedback: Has some problems

Picture of Christian Lawson-Perfect

Christian Lawson-Perfect 2 years, 2 months ago

Saved a checkpoint:

Advice for part a could show each sequence with the common differences underneath, so it's easy to see which are linear. That's how I'd work it out.

Similarly with common ratios for part b.

For part c, I just use the fact that the difference between consecutive triangle numbers increases by 1 at each step. A drawing of the first few triangle numbers would help show this. While you can use the formula, it's not obvious, and you'd look at common differences first.

In part d, rather than using the triangle sequence in particular, I'd give a formula of the form $\frac{an(n+b)}{c}$ (what constraints are there on randomising this?) - you want to see that the student's comfortable with using a formula to get the nth term of a sequence without working out all the previous terms.

Part e relies on noticing that the sequences are the squares and cubes, respectively. How would you work this out? It's not enough to just state it in the advice. You might look at common differences, then make a guess that it's $n^2$ or $n^3$. The advice should show this experimental thinking - is it really $n^2$? How do we check? Draw a table of $n$ against $a_n$?

Restore this checkpoint

Hannah Aldous 2 years, 2 months ago

Gave some feedback: Needs to be tested

Hannah Aldous 2 years, 2 months ago

Created this as a copy of Finding the $n^{\text{th}}$ Term of a Quadratic Sequence.
Name Status Author Last Modified
Arithmetic sequences in an ice cream shop Ready to use Hannah Aldous 01/08/2017 13:41
Compute the partial sum of an arithmetic sequence Ready to use Hannah Aldous 01/08/2017 13:32
Finding the $n^{\text{th}}$ Term of a Quadratic Sequence Ready to use Hannah Aldous 01/08/2017 13:28
Identifying different types of sequences Ready to use Hannah Aldous 14/05/2019 14:52
Finding the formula for the $n^{\text{th}}$ term of linear sequences Ready to use Hannah Aldous 01/08/2017 13:40
Partial sum of an arithmetic sequence - birthday money Ready to use Hannah Aldous 01/08/2017 13:45
Find common difference in arithmetic sequences with gaps Ready to use Christian Lawson-Perfect 01/08/2017 13:56
Fill in the gaps in an arithmetic sequence Ready to use Christian Lawson-Perfect 01/08/2017 13:57
Write down and apply the formula for an arithmetic sequence. Ready to use Christian Lawson-Perfect 01/08/2017 13:57
Finding the Formula for the $n^{\text{th}}$ Term of Linear Sequences draft Chris Graham 20/07/2017 15:08
Inbbavathie's copy of Find common difference in arithmetic sequences with gaps draft Inbbavathie Ravi 24/07/2017 03:48
Find a particular term of a sequence using the given formula Ready to use Christian Lawson-Perfect 01/08/2017 13:31
Johan's copy of Write down and apply the formula for an arithmetic sequence. Has some problems Johan Maertens 02/08/2017 17:51
Finding the formula for the $n^{\text{th}}$ term of linear sequences draft steve kilgallon 19/11/2017 08:09
Compute the partial sum of an arithmetic sequence draft steve kilgallon 19/11/2017 08:11
Identifying different types of sequences draft Luis Hernandez 31/12/2018 01:38
Calcular la suma parcial de una sucesión aritmética Ready to use Luis Hernandez 14/01/2019 17:37
Identificando diferentes tipos de secuencias Ready to use Luis Hernandez 14/01/2019 13:19
Suma parcial de una secuencia aritmética - Cumpleaños Ready to use Luis Hernandez 14/01/2019 19:01
Encontrar la diferencia común en una Secuencia Aritmética Ready to use Luis Hernandez 14/01/2019 17:40
Encuentra un término particular de una secuencia usando la fórmula dada Ready to use Luis Hernandez 14/01/2019 17:48
Encontrar la fórmula para el término $n^{\text {th}}$ de una secuencia lineal Ready to use Luis Hernandez 14/01/2019 19:29
Simon's copy of Write down and apply the formula for an arithmetic sequence. draft Simon Thomas 25/02/2019 10:20
Simon's copy of Find common difference in arithmetic sequences with gaps draft Simon Thomas 25/02/2019 10:24
Simon's copy of Finding the formula for the $n^{\text{th}}$ term of linear sequences draft Simon Thomas 25/02/2019 10:30
Identifying different types of sequences draft Xiaodan Leng 10/07/2019 21:48
Write down and apply the formula for an arithmetic sequence. draft Xiaodan Leng 11/07/2019 01:48
Fill in the gaps in an arithmetic sequence draft Xiaodan Leng 11/07/2019 01:48
Find common difference in arithmetic sequences with gaps draft Xiaodan Leng 11/07/2019 01:49
Compute the partial sum of an arithmetic sequence draft Xiaodan Leng 11/07/2019 01:51
Partial sum of an arithmetic sequence - birthday money draft Xiaodan Leng 11/07/2019 01:54
Arithmetic sequences in an ice cream shop draft Xiaodan Leng 11/07/2019 01:55
Finding the formula for the $n^{\text{th}}$ term of linear sequences draft Xiaodan Leng 11/07/2019 01:55
Find a particular term of a sequence using the given formula draft Xiaodan Leng 11/07/2019 01:56
Finding the $n^{\text{th}}$ Term of a Quadratic Sequence draft Xiaodan Leng 11/07/2019 01:57

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