I'm PRIME!

Prime Numbers!

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Prime numbers are an infinite set of whole numbers that are only divisible by 1 and the number itself. (example: 13/1=13 and 13/13=1 There are no other divisors).

Some reminders about prime numbers are:

*Number 1 is not a prime number but rather a natural number.

*Any even number that is greater than 2 is not prime. 

Sound easy enough to teach? Well, the ability to know what the divisors are can be complicated. A student needs to have the skill of factorization and division well understood in order to find those prime numbers. 

This rap is a great way to get them to remember as well. Music has an amazing way of teaching concepts and being able to recall easily. After watching this video, ask students to prepare their own rap. By using the information they know, they will recall it well into the future and not just for a test. 

Prime Numbers Rap Typography 

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Have students rediscover factors for reinforcement if needed. This is a fun game similar to "Who Wants to Be a Millionaire" that will be an effective way to review instead of just reviewing on the board. 

Factors Millionaire Game

Depending on the grade, have students find prime numbers up to a certain number (for example, 4th graders can get to the 300's easily since they know their factors and division quite well, whereas 3rd grade can perhaps get to the 100's).

Prime Numbers Game

Fruit Shoot-Prime and Composite

Order of Operations

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When students see so many symbols on math problems, it can be overwhelming. Getting a grasp on number sense is first but then figuring out how they can be used to add, subtract, multiply and divide is a feat within itself. Now add parentheses and it may be just too much clutter for some. 

So, how can we help students remember the order of operations? One strategy that has been around for a while is to remember PEMDAS. PEMDAS is an acronym for Parentheses, Exponents, Multiplication, Division, Addition and Subtraction (in that respective order). Students need to then be reminded to work left to right. Many people use the acronym Please Excuse My Dear Aunt Sally.

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Here's an example: 7 - 9 x 3 + 4=
If you start from left to right without PEMDAS you will find the answer to be 2.

With PEMDAS, you will find the answer to be -16. 

Start with 9 x 3=27. Then, 7-27= -20 + 4=16.
The order of operations must be in place to find the correct answer.


Another example: 7 x (4+3) =
Start with 4+3 as it is in parentheses. Answer 7. Now, 7 x 7 = 49. 
Without PEMDAS and working from left to right, you would get 31. A big difference!

Here's a fun video!

PEMDAS - Order of Operations RAP

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Try out these interactive games as well:
Order of Operations Millionaire Game
Fun Brain (various levels of difficulty available)

Mean, Median, Mode, and Range!

Mean, Median, Mode and Range

Many times when studying mean, median, mode and range, students get confused, however if we can help them make connections with the meaning of the word or with a way to remember what it is asking, they are bound to be successful. The more repetition, the better.

Let's start with mean. Mean sounds much like the word mean when referring to the way the students may think of you for making them do this! Remind them that you are not mean, but sometimes the process may seem that way since it takes a while. Add all the numbers in the data set up and divide them by the number of numbers in the data set.
Example:

31, 24, 26, 33, 33, 29, 27

31+24+26+33+33+29+27=203        203/7=29      29 is the mean.

Moving on to median...Have students line the numbers up in order from least to greatest. Then the clue is to find the middle, which is similar to the word medium, which is often a middle size.
Example:

24,26,27,29,31,33,33       29 is the median. 

If however you have an even number of numbers, remind students to add the two middle numbers and divide by 2 to find the median.

Range is the difference between the largest and smallest values in the data set. Looking at the numbers in the data set, find the largest and smallest and subtract to find the difference. In this case it is: 33-24= 9
I like to remind students that a range is a big open area. So, the numbers stretch from smallest to largest.

Finally, finding mode is probably the easiest. Mode is the "moda" (fashion in Spanish) and the number that appears most often (number of highest frequency). Not every data set has a mode. In this case it does. The mode is 33 since it is repeated. If there is a 24, 24, 33, 33, 33. The mode would be 33 since it is repeated most often.

Here are a couple videos related to finding mean, median, and mode. Remember, make it fun!

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