8th Grade Unit 6: Exponents (Part 2 Scientific Notation)

I shared part 1 of our unit on exponents here.


I got most of my notes from Sarah’s blog.  She also has a ton of activities on her blog here.

Screen Shot 2018-06-22 at 3.16.59 PM.png

 

As I was writing this, I remembered this image that Heather shared from one of Sara’s presentations.  I think this would be a GREAT way to introduce scientific notation next year.  I’ve got to remember to do that!

The last couple years, I’ve used tables similar to those below to help students notice patterns.

Screen Shot 2018-06-22 at 3.15.12 PMScreen Shot 2018-06-22 at 3.15.20 PM

After we talk about converting between standard form and scientific notation, I’ve used this Desmos activity.  I also like this Desmos activity.

Screen Shot 2018-06-26 at 11.28.56 AM.png


Then we get into multiplying and dividing numbers in scientific notation.

I made this Desmos activity for practice.

Screen Shot 2018-06-26 at 11.33.34 AM.png

The biggest thing my students struggle with at this point in the unit is when they multiply or divide and get a number that isn’t in scientific notation.  Something like 64 x 10^6.  They know the exponent will change by one, but many students get mixed up on whether it gets bigger or smaller.  I always, “Don’t try to memorize a “shortcut”.  Think about what 64 x 10^6 is.  Write it out in standard form, and then convert it to scientific notation.  Then you don’t have to try to memorize anything.”  The students that listen and follow my advice, usually have no issues with this, but it’s the students who want to take a “shortcut” that end up not getting these problems correct.  Please tell me I’m not the only one who has this issue!


I’ve got a couple Which One Doesn’t Belong? warm-ups for scientific notation.  I know I pulled the second one from Twitter.  I can’t remember who shared it.  If it’s yours, please let me know so I can give you credit for it.

Screen Shot 2018-06-26 at 11.39.26 AMScreen Shot 2018-06-26 at 11.39.33 AM


I’ve used this scavenger hunt as well.  I like that it gets students up and moving around.

Screen Shot 2018-06-26 at 11.43.48 AM.png


I created this worksheet for students to practice.  (I think I created it.  I may have modified it from somewhere.  Again, if you recognize it, please let me know so I can give credit to who originally created it.) . You can download it here.  I’ve created a few other worksheets of this format and like that it’s self checking for students.

Screen Shot 2018-06-26 at 11.42.45 AM

Advertisements

8th Grade Unit 5: Systems of Equations (Part 2 – Elimination & Choosing Method)

I shared here part 1 of our unit on systems of equations -solving by graphing and by substitution.


Elimination

I started this unit with the following warm-up.

Screen Shot 2018-06-08 at 8.28.17 PM.png

Then I followed it up with this notice/wonder.

Screen Shot 2018-06-08 at 8.28.29 PM.png

One of my students this past year noticed that, “These are like the problems we did for warm-up.”  I love when my students notice connections between the warm-up and the lesson for the day and that I’m not just having them do random stuff.

I was really pleased with how this led nicely into the lesson for the day.  Students noticed that in each problem there was a zero.  They were able to tell me why that happened.  When I told them that this is another method for solving systems of equations called elimination, at least someone in each class was able to explain why they thought that elimination was a good name for this method.

It had been a while since we had done Vertical Non-Permanent Surfaces, and these problems work great for that.

IMG_7672


Choosing Method

The last part of this unit was having students choose the best/most efficient method for solving a system of equations.

I started with this Desmos Activity.  I didn’t have students solve the systems the first day.  I wanted them to just think through what method they would want to use to solve each.  The next day they actually solved some of the systems.

Screen Shot 2018-06-08 at 8.45.11 PM.png

I love this Desmos Activity from Paul Jorgens.

Screen Shot 2018-06-08 at 8.46.05 PM.png


I’ve uploaded some of the worksheets and notes I used from this unit here.

8th Grade Unit 5: Systems of Equations (Part 1 – Graphing & Substitution)

Graphing

Even though this is Unit 5 in 8th grade, this is the unit I’ve done last the past couple years I’ve taught it.  It just worked out that way my first year teaching 8th grade, and I liked it that way so I did it again this past year.  I like having it at the end of the year because it’s a good way to review graphing lines.

I start the unit by spending a half day or so on just a review of graphing lines.  I almost didn’t do that this year, but was SO glad that I did.

Then we do Desmos Polygraph and this Desmos activity to intro systems of equations.

Screen Shot 2018-06-08 at 7.56.13 PM

Then we spend some more time practicing.  I’ve used this Desmos activity in the past.

After that we get into systems of equations that have no solution or infinite solutions.  I usually start by putting up one of those types of problems without giving students any explanation.

Screen Shot 2018-06-08 at 8.12.03 PM.png

Students have had a lot of experience solving problems with no solution or infinite solutions by this point in the year, so I usually have some students who come up with the fact that because both equations are the same line, there are infinite solutions.


Substitution

I blogged here about how I introduce substitution to students.  I’ve used this method 3 years in a row and am still amazed every. time. how smoothly it goes.


Here is the link to download some of the worksheets I use for this portion of our unit.

8th Grade Unit 4: Applications of Lines

We start our unit on applications of lines by discussing independent and dependent variables.  I have a note to myself to remember to use the following language next year because it worked well this year.  Nothing earth shattering, I know.

  • “(independent variable) causes change to (dependent variable)”
  • “(dependent variable) depends on (independent variable)”

I use a lot of Sarah’s resources found here for my notes, and I’m pretty sure that’s where I got the problems for this Desmos activity.

Screen Shot 2018-06-13 at 8.31.23 PMScreen Shot 2018-06-13 at 8.31.30 PM

The next day we do Sarah’s Ghosts in the Graveyard activity with independent and dependent variables.  Every time I use that activity I think to myself, “Why don’t I do this more often?  It’s great!”

After students have a pretty solid understanding of defining the dependent and independent variable, writing linear equations from word problems goes a lot better.


Then we get into parallel and perpendicular lines.  I blogged briefly about what I did last year here.

I start with parallel lines and use this Desmos activity.  One of the downfalls of starting with that activity is that when students are asked to solve problems where they need to write the equation of a line parallel to a given line through a specific point, they want to use Desmos to guess and check.  This is a good strategy, but I also want them to know another method.  I start the next day with a couple problems like these.

Screen Shot 2018-06-06 at 8.45.39 PM

After spending another day or so on parallel lines, we finally get into perpendicular lines.  I start with this Desmos activity.

Screen Shot 2018-06-06 at 8.48.32 PM.png

We spend another day or so practicing with perpendicular lines.  I’ve used this activity before and like how it brings back different forms of lines.

We also talk a little bit about parallel and perpendicular lines and quadrilaterals using this Desmos activity.

Screen Shot 2018-06-06 at 8.56.43 PM


Then we get into scatter plots.  I start with this Notice/Wonder

Screen Shot 2018-06-06 at 9.08.55 PM.png

We do Desmos Polygraph next.  Last year I had a student ask if there were two “loners”, and I will forever think of outliers as loners.

After students do that activity, I put the graphs up on the board and ask students to put them in groups.  They end up describing the different correlations to me.

Screen Shot 2018-06-06 at 9.15.43 PM.png

This Which One Doesn’t Belong? is great around this time in the unit.

Screen Shot 2018-06-06 at 9.29.34 PM

I took a couple tasks from this page and turned them into Desmos activities.  (I know she tweeted out links to the activities at one point, but I couldn’t find them.

Here’s one on correlation.

Screen Shot 2018-06-06 at 9.37.06 PM

And another on lines of best fit.

Screen Shot 2018-06-06 at 9.37.19 PM


Here is the link to download some of the worksheets I use in this unit.

VNPS Variation

(VNPS: Vertical Non-permanent surfaces)

IMG_8856

This is a different time we did VNPS, but my classroom looks like this nearly every time we do this.  Why don’t I do this more often??

Last year I created a “Two Truths and a Lie” worksheet on exponent worksheets.  Students simplify three problems.  Two of the answers are the same, and the third answer is similar but not quite the same.  I was really happy with how the worksheet turned out and how it went last year.

The day I had this worksheet in my lesson plan, I realized I wasn’t really looking forward to another worksheet with my 8th graders.  I try to mix things up, but lately they’ve had worksheets pretty consistently.  I was thinking through other options and was trying to come up with a way to change things up less than 2 hours before I had students in my room.

Screen Shot 2018-04-05 at 8.33.32 PMScreen Shot 2018-04-05 at 8.33.43 PMScreen Shot 2018-04-05 at 8.33.49 PMScreen Shot 2018-04-05 at 8.33.54 PMWhiteboards!  I realized it had been a while since I’d had students work at the whiteboards.  I took screenshots of the problems, projected them on the board, and had students work in groups through the four problem sets.

In the past when students worked at the whiteboards, I had them do one problem at a time and get it checked by me.  This time, I had students do all three problems in each set before I would check their answers.  They knew that two of the answers were going to be the same and one would be slightly different, so they already were doing some self-checking as they went along!  When students called me over to check their answers, I would tell them how many problems they had wrong but wouldn’t tell them which one.  I really liked the small change in how I had students do these problems.  This is something I do a lot when they’re working in Desmos or with other activities, but I hadn’t done it in this situation before and loved how it went.

I had more students engaged for more of the hour by doing the problems this way, and my students were talking through the problems more than they would have if they were working on the worksheet.  I actually had students cheer when I said we were going to the whiteboards.  🙂 It was a good reminder that I don’t have to always come up with some fancy activity to switch things up.  Something as simple as taking problems from a worksheet and having students complete them in a different way is enough sometimes.


Here’s the link to download the worksheet and others on exponents.  Here is where I shared other things I did in this unit last year.

8th Grade Unit 3: Functions (Part 3 – Point Slope Form & Standard Form)

Here’s part 1 and part 2 of unit 3.


I used this warm-up the first day after our test on slope-intercept form to get students thinking about equations and graphs again.

Screen Shot 2018-02-03 at 11.26.24 AM.png

Then I do notice/wonder with this.

Screen Shot 2018-02-03 at 11.26.34 AM.png

I heard things like:

  • There are two x’s and two y’s.
  • There are little 1’s by one of the x’s and one of the y’s.
  • There are parenthesis.
  • There’s an m (slope).
  • There’s no y-intercept
  • Is it another form of a linear equation?

It leads nicely into discussing point-slope form and students realize that it isn’t as scary as it may look at first because they recognize the similarities between slope-intercept form.

When going over point-slope form, I make a point to emphasize to students why it’s named point-slope form -we can see the coordinates of a point and the slope from the equation.  I remind them that this is similar to slope-intercept form where we saw the slope and the y-intercept.

Then we go over a few examples of writing equations in point-slope form before doing an activity similar to what Sarah shared here.  I didn’t have big foam die like Sarah used, but I do have double dice, which students always think are fun.  Students rolled the dice to create two ordered pairs and wrote an equation in point-slope form of the line between those two points.  Then they checked their answers using Desmos.  Having students check with Desmos was key to helping them see what they were doing when writing the equation of the line.

I also modified this Desmos marbleslides activity to rearrange the equation so that they looked like what my students were used to seeing.  My modified version can be found here.


Then after some more practice using point-slope form, students are introduced to standard form.

I use notice/wonder again to get students thinking about this.

Screen Shot 2018-02-03 at 11.41.21 AM

Again, students came up with the following things:

  • There’s 2’s in all of them.
  • The two is always by the x.
  • One of the equations is in slope-intercept form.
  • One of the equations is in point-slope form.
  • In the purple one, the x and y are on the same side.

We also talk about how, unlike slope-intercept form and point-slope form, we don’t see the slope, the y-intercept, or a point.


Of the three parts to this unit, this one is takes up the fewest number of class periods.  Writing up this post made me realize that I could probably use a few more activities on these concepts.  If you have any ideas for me, please share!

8th Grade Unit 3: Functions (Part 2 – Slope & Slope Intercept Form)

After talking about functions vs relations and linear vs nonlinear, we get into slope and slope intercept form in 8th grade.


Slope

To intro this I start by using a Desmos Polygraph.

Screen Shot 2018-01-21 at 4.32.48 PM.png

Then this year I tried this Desmos activity on steepness.  I liked we were able to move from talking about something students were familiar with, steepness, to a word students may not be familiar with in slope.

Screen Shot 2018-01-21 at 4.29.51 PM

Then I was able to use use this awesome activity Sarah shared here with some of my students, since they were a couple days behind the other class.  It was such a simple idea, but I absolutely LOVED how students figured out on their own how to find the slope of a line.  They also were able to explain when slope would be positive versus negative.  For next year, I might change some of the lines to include slopes such as 2/3 or 3/4.

And what would be a lesson on slope without Slope Dude?  I blogged about another activity I shamelessly stole from Sarah here.sd2

I used this Desmos activity I found online to have students practice finding the slope of lines.  After that, we talk about the slope of horizontal and vertical lines.  Students already know from playing Slope Dude that horizontal lines have a slope of zero and vertical lines have an undefined slope, but now we talk about why.

Screen Shot 2018-01-21 at 4.47.55 PM.png


Slope Intercept Form

A while ago on Twitter Mickie asked for ideas on introducing Slope Intercept Form to students.

I shared with her a worksheet I created a few years ago where students use Desmos to figure out slope-intercept form.  She had some great ideas of how to improve what I had created.  (Twitter and #MTBoS are so great!)  She shared with me what she and a colleague came up with.  I loved her addition of the table.  Here‘s the editable version of the worksheet she shared with me -I did make a few minor changes.

Screen Shot 2018-02-02 at 11.42.51 PM.png

When I’m teaching slope-intercept form, I try to make a big deal about how the name for this form of an equation makes sense based on the formula itself.  When we’re given an equation in this form, we can easily see the slope and the y-intercept, hence the name slope intercept form.  This is something that is obvious to me as the teacher, but I found that students don’t always make this connection.  Because of that, it’s important for me to help students make that connection.  This also helps later on when we talk about point-slope form.

One change I made this year to how I teach this is that I had students check their answers after graphing.  I decided to do this for a couple reasons.  One, I hoped that this would slow students down and help them catch mistakes they made when doing the slope of the line.  Two, I hoped that this would help students make the connection between the graph and the equation.  In the past, I don’t know that I have done a good job of helping students make this connection.

After students are comfortable with equations in slope intercept form, we go over writing an equation from a graph, writing equations for horizontal and vertical lines, as well as needing to get y by itself before graphing.

Here is the link to a Desmos activity I used to have students practice going from graph to equation.  I took the images from somewhere online, but I can’t remember where.  Sorry!  If anyone recognizes them, please share so that I can give whoever created them credit.

Screen Shot 2018-01-30 at 7.08.09 PM

You can download a worksheet and the test review here.

And last but certainly not least:  Desmos Marbleslides.  This is one of my absolute favorite activities from Desmos.

Screen Shot 2018-01-21 at 5.13.25 PM