Tag Archives: distance

Writing Equations of Lines – with Some Novetly


So I picked up some packs of foam number cubes at Mighty Dollar last week.  I sat wondering – what could I do with these?  Finally, during supper one night – an idea came across.  I’d use them to generate coordinates of points and students could write equations of lines.  Hmm.

2013-02-03 14.52.59

But as is, all points would fall in Quadrant I.  On half of the dice, I added a negative to 1, 2, 3 and the other half, onto 4, 5, 6.  So, have students roll the dice…thanks to ROY G BIV, we’ll know what order to place them for some consistency.

2013-02-03 14.56.50  Students record the coordinates of 3 points.  2013-02-03 14.57.33

Directions will be:

  1. i. Find the slope between RO & YG.
  2. Write an equation of a line that passes through RO & YG in slope-intercept form.
  3. Write an equation of a line parallel to ROYG and through the 3rd point IV.
  4. Write an equation of a line perpendicular to ROYG and through the point IV.
  5. Find the midpoint coordinates.
  6. Calculate the distance between RO & YG.

Yes, skill and drill – but with a bit of novelty, hopefully to engage the students a bit more than a black & white worksheet.

I’ve read several posts about activities similar to this – they are not easily assessed.  Students in the group – hold each other accountable.  I prefer same ability grouping – this allows students who are able to move along – while I can spend time with a student who has been absent/struggling to catch them up.  I purposefully walk around the room and spot-check each group to ensure they are on the right track.  If students are recording their coordinates/work/equations – its very easy to take up their work and spot check 2 or 3 sets to ensure correctness.


Sometimes when working in small groups  such as this – I like to have the stop light cups out – If students are okay, the green cup is showing, if they have a question – but can keep on going, the yellow cup and finally, if they need my help – the red cup showing.  I can easily glance around the room for a quick look to see how everyone is doing.



Geo-board Investigations


I was clearing out some files this weekend and ran across this packet from a presentation at KCTM in 2002.  I had just completed my initial National Board Certification earlier that spring (still didn’t know if I had certified yet) and thought these lessons were worth sharing.

I’m not sure if you’ll be able to read the first two pages – orginal files are long gone and just by happenstance I rance across this packet.  Reading through it – its almost like I was “blogging” 10 years ago – but it reminds how important reflection on your lesson will always be – how much you can learn about teaching by pausing to think about student thinking/responses.  Whether you use actual geo-boards, paper/pencil or modify to www.geogebra.org – maybe they will give you some ideas for your classroom.

Geo-board Investigations

  • Parallel & Perpendicular Investigation – use rectangle properties to find relationship with slopes
  • Amusement Park – distance between 2 points (I hate using distance formula and often allow students to find slope triangle, then apply Pythagorean Theorem)
  • Midpoint Investigation
  • Midsegment Investigation

*I used the reinforcement tabs for students to write coordinates/label points on geo-boards.  BUT don’t let them peel and stick…just leave on paper and drop over the geo-board tab.