New
New
Year 8

Checking and securing understanding of plotting coordinates with technology

I can use technology to quickly represent a set of coordinates graphically.

New
New
Year 8

Checking and securing understanding of plotting coordinates with technology

I can use technology to quickly represent a set of coordinates graphically.

Lesson details

Key learning points

  1. A table can be used to plot coordinates on Desmos.
  2. It is easy to see if any of the points do not fit the pattern.
  3. It is possible to draw a line through the points using Desmos.
  4. Using the line you can determine if points do or do not fit the rule.

Common misconception

When plotting the sequence $$3n-1$$ using technology you need to type each coordinate individually.

"We use technology to make things easier. There must be a quicker way!" Look for the 'table' function.

Keywords

  • Arithmetic (linear) sequence - A sequence where the difference between successive terms is a constant.

Get pupils to plot the first ten terms of $$3n-1$$ then say, "Do it for 100 terms". Allow a minute before interrupting with, "There is a quicker way! A table function which plots multiple points in seconds. Can you find it?". Allow pupils to explore.
Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
The vertical and horizontal lines that divide our coordinate grid into the four quadrants are called ...
Correct answer: axes
grid lines
parallel lines
Q2.
Which of these is a correctly formatted coordinate?
$$2,7$$
$$(2/7)$$
$$2:7$$
$$(2$$ $$7)$$
Correct answer: $$(2, 7)$$
Q3.
Which of these coordinates fits the rule "The $$y$$ coordinate is five times the $$x$$ coordinate minus $$1$$?
$$(0, 1)$$
Correct answer: $$(0, −1)$$
$$(5, 4)$$
Correct answer: $$(5, 24)$$
$$(5, −1)$$
Q4.
Which arithmetic sequence is represented by this table of values?
An image in a quiz
$$n+7$$
$$7n+7$$
$$7(n+7)$$
Correct answer: $$7n$$
Q5.
Arithmetic sequences have which features?
Correct answer: A constant difference between terms.
Correct answer: They form a straight line when plotted.
They form a curve when plotted.
Increasing values.
Q6.
Which relationship is represented by this table of values?
An image in a quiz
Correct answer: $$y=6−2x$$
$$y=x−2$$
$$y=2x−6$$
$$y=8−2x$$

6 Questions

Q1.
Which words describe this plotted sequence?
An image in a quiz
Correct answer: linear
Correct answer: arithmetic
increasing
Correct answer: decreasing
quadratic
Q2.
Why did the software not plot the coordinate $$(3, 5)$$ in this image?
An image in a quiz
Because $$3$$ and $$5$$ aren't labelled on the $$x$$ and $$y$$ axes.
The scale on the axes is wrong.
We are zoomed in on the wrong region of the graph to see it.
Correct answer: You have to write the coordinate pair in brackets.
Q3.
Which arithmetic sequence is represented here?
An image in a quiz
$$n$$
$$−2n$$
$$5−2n$$
Correct answer: $$7−2n$$
Q4.
How do we know that $$(2,−3)$$ does not follow the same linear rule as the other coordinates?
An image in a quiz
It's in the wrong quadrant.
It's plotted wrong.
Correct answer: It doesn't align with the other coordinates.
Because the $$y$$ coordinate is less than the $$x$$ coordinate.
Q5.
Which term is incorrect in this arithmetic sequence?
An image in a quiz
The $$1^{\text{st}}$$ one
The $$3^{\text{rd}}$$ one
Correct answer: The $$5^{\text{th}}$$ one
The $$7^{\text{th}}$$ one
Q6.
Which coordinate fits both of the rules $$y=8−x$$ and $$y=3x−4$$?
An image in a quiz
$$(0, 8)$$
$$(8, 0)$$
Correct answer: $$(3, 5)$$
$$(5, 3)$$
No coordinate fits both rules.