Discussion in 'Elementary Education Archives' started by AngelHead, Feb 19, 2007.

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Feb 19, 2007

I just learned that my unit on fractions and decimals is also supposed to encompass probability. Does anyone have any good lesson plans for this content? This is the exact content I'm supposed to teach:

- Describe the likelihood of an event as certain, impossible, likely, or unlikely

-Determine all possible outcomes in simple probability activities (up to six outcomes)

-Use fractions to represent simple probabilities

I'm not even sure I know what this means, so that makes teaching it quite difficult. Any guidance would be much appreciated!!!

2. 3. ### czaczaMultitudinous

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Feb 19, 2007

Marilyn Burns has some probability books- the one for 3rd grade uses spinners.

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Feb 19, 2007

Well, you really should read a few good chapters in texts and also look for some websites to familiarize yourself before teaching it. Yes, probability is taught in elementary. Check out the lessons here at AtoZ first. Here are the basics:

Probability is the likelihood that a particular event, or outcome, will occur. It is expressed as a fraction with the numerator being the total number of favorable outcomes, the denominator being the total number of possible outcomes.

The first step is always to look for the total number of possible outcomes. So, for a coin toss, the total number of possible outcomes is just two - heads or tails. For a toss of a standard die, the total is six.

For third grade, you will keep it very simple, and will stick to single events. Ex: What is the probability of rolling a 5 on a regular die? This is written as P(5). The answer is 1/6, since there is only one side marked 5 out of six different outcomes.

You might get to single events with two different methods, however. Ex: If you toss two coins, what is the probability that you will get a head? P(H). In this case you first show the total number of possible outcomes, which are: HH, HT, TT, TH. There are four possible outcomes. Ask how many times heads appears. It appears three times. Therefore, the P(H) is 3/4.

All of this explanation is about theoretical probability, which you don't have to tell them. Be aware, though, that if you do experiments (which the kids love to do), that the actual results will likely differ from the experimental probabilities. This is because you would have to do innumerable repetitions to consistently get results that mimic the theory.

The students may be able to understand that if the probability of something occurring is 1/6, then out of, say, 24 tries, you would expect to get the favorable result four times. Demonstrate this with manipulatives or on the board by selecting one item out of each group of four from the total of 24. However, merely repeating the experiment 24 times will not guarantee that you will get the favorable outcome exactly four times.

There. Have I confused you enough? I hope not.

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Feb 19, 2007

Thanks. That makes sense. Does anyone have any lesson ideas for this content? My fractions and decimals unit was going to difficult enough, but putting probability into the mix is going to put some of my kids over the edge, if not me.

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Feb 20, 2007

7. ### DTMRookie

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Feb 20, 2007

I just did a probability lesson with my kids (2nd grade) using candy conversation hearts (for Valentines Day). Each of the kids were given 10 hearts, placed them in a bag and randomly pulled out a heart, graphing the colors that came out. Before they did this on their own, I modeled with them and we discussed the probability of pulling out a certain color. I used three colored hearts, but my graph had 4 colors, the fourth color being "impossible" because I only 3 colors. I purposely had more of a certain color so we could discuss one color being likely, the other being unlikely, etc. The kids enjoyed this activity and it was a good way to introduce them to the vocab. associated with probability.

The cool thing about probability is you can incorporate it into anything you do with your kids. For example, pull out some spare change from your pocket and say I have 3 dimes, 6 pennies, and 1 quarter, what are the chances I'll pick a dime if I randomly pull a coin from my pocket? Etc., etc. We even discussed the chances that the children would have a male or female teacher when they went to 3rd grade, 4th grade, etc. using how many teachers of each sex there are at each grade level in our school.

I hope these ideas help!

8. ### TeacherGroupieModerator

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Feb 20, 2007

AngelHead, one thing to point out to your kids is that, once they've figured out what the fractions are, the fractions then behave like regular ol' fractions - they add/subtract/multiply just as ordinary fractions do.

So one way of looking at 'daisy's example of tossing the two coins is that you've got a 1/2 probability of getting tails - the result you don't want - on each coin. The probability of getting tails on BOTH coins is then 1/2 x 1/2 = 1/4. And since the probability of getting either-heads-or-tails on both coins is 1, the probability of getting heads on at least one coin has to be 1 - 1/4 = 3/4.

9. ### teacherintexasMaven

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Feb 21, 2007

When I taught third grade and taught probability, I didn't even get out a math book the first day. We just used examples with materials in our classroom until they got the hang of it. The kids asking to make up problems before the thirty minutes or so were up. The next day, when starting to do probability with paper/pencil, they were so excited, which was exciting for me since I had quite a few students who "hated math" or so they said.

Start with certain and impossible since those are the easiest for the kids to see, then likely and unlikely. Once they have the vocabulary, introduce naming the possible outcomes and then (verbally) naming with fractions before you ever use paper.

10. ### ellen_aGroupie

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Feb 21, 2007

I used Marilyn Burns spinners when teaching probability in an undergraduate practicum (to inner-city fourth graders). We started with a sort for likely, certain, impossible, etc. Then we did some experimentation with different spinners, so students could deduce that the more of something in a set, the more likely it is that you'll obtain that result. We did some modeling/direct instruction/guided practice writing probability results as fractions, and then I set up a hands-on (book writing) activity for them to practice this skill.

My kids loved the Marilyn Burns spinners, so I used those as an activity as well--they created their own to meet a specific probability equation as specified by myself. Once they got it right, we put the spinners together. They loved those spinners.

11. ### TeacherGroupieModerator

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Feb 22, 2007

That's cool, ellen_a!

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