Linear: The Seven Dwarves

 Algebra with The Seven Dwarves

Tweet me at @aanthonya if you have questions about this activity.

I find that even at the point when my 9th grade students reach High School, they still don't really "understand" even the basics of linear equations.   Sure, they can remember how to calculate slope once I remind them of the slope formula, but they don't know what it means.  Y-intercept.....forget it.  They just don't get it.

So....I usually throw in a little problem in the first week or so where we will construct two lines using all the stuff they probably covered in middle school.

This simple example hopefully is something I can reference throughout the year as an example.  The example works well for various topics, especially linear and linear systems.

These video examples are reduced in size to save space.  The versions I use inclass are much higher quality and size.

version 1:

version 2:

 Here are some screenshots from the SMARTBoard presentation I use to build the problem and graph it step by step.

Algebra and Marbles

A couple of days ago I bought 6 bags of marbles.  There are 50 marbles in each bag.  I would like to make at least 3 Algebra activities using these marbles.

Here's one I think is cool:

1. Start with 2 jars, one filled with marbles and the other empty. Give students the weight of the filled jar and also of the empty jar.

2. Then give students a supply of marbles and an empty jar.  I imagine doing this in small groups.

3. Students use algebra to determine approx. weight of 1 marble, 2 marbles etc....

4. The challenge is to find the weight of one marble without weighing anything or opening the first jar.

5. Let them play and problem solve.

6. [y=mx+b] They should discover that the full jar weight = (# of marbles) (weight of one marble) + weight of empty jar. They need to reason it out to get to this point.

7. In order to know how many marbles are in the full jar, they can use the empty jar and fill it with marbles, then count approximately how many marbles are in the first jar. So it's important to use "approximately".

8. Students can solve for weight of one marble using algebra.

I like this activity because they won't feel like they are using algebra until then end.  At that point the algebra should make sense.  What do you think?  Can you come up with any more activities?