Factors of 21

Thursday, March 21, 2019

Learn to find the factors of the number 21. The number 21 is a composite number, as a result, it is divisible by numbers other than itself and 1.

The factors of 21 are 1,3,7,21

The prime factors are 3 and 7

There are shortcuts that help you determine if a number is divisible by another. For example, if a number ends in zero or is even then it is divisible by 2. You can download this chart to learn these rules.

Divisibility Rules Chart

Finding factors playlist

Factors of 100-Includes Prime Factorization

100 is a composite number. As a result numbers other than 1 and itself divide into 100.

The factors of 100 include,

1,2,4,5,20,25,50 and 100

The prime factors of 100 include,


Learning these shortcuts speed up the process of finding factors.

Divisibility Rules Chart

Need help learning how to find factors? This playlist will help.

Finding factors playlist

Divisibility Rules

Sunday, March 17, 2019

Learning these divisibility rules can help you a great deal when finding the factors of a number.
These rules can also help when finding the LCM and GCF

Divisible by 2
The number ends in an even number then it is divisible by 2

Divisible by 3
Add the digits of the number together and if the sum is divisible by 3 the entire number is divisible by 3

Divisible by 4
If the last two digits are divisible by 4 then the original number is divisible by 4

Divisible by 5
If the number ends in 5 or 0 then the number is divisible by 5

Divisible by 6
If the number is divisible by 2 or 3 then the number is also divisible by 6

Divisible by 7
Multiply the last digit by 2 then subtract this from the remaining number, if this number is zero or divisible by 7 then the number is divisible by 7.

Example: 168
8 x 2 = 16
16-16 = 0
7 x 24 = 168

Divisible by 8
Divide the number by 2 twice, if this number is even, then the number is divisible by 8
64   64/2 = 32
       32/2 = 16 which even so 64 is divisible by 8
        8 x 8 = 64

Divisible by 9
If the sum of the digits is divisible by 9 then the number is divisible by 9
72   7+2 = 9
       9 /9 = 1
       9 x 8 = 72

Divisible by 10
If the number ends in zero, the number is divisible by 10

Download Divisibility Chart

divisibilty chart

Learn Science Variables with the Walking Water Experiment

Thursday, February 28, 2019

Walking water is a fun experiment that you can use to teach or learn all about Science variables.
In this video, I show how to set up the demonstration " walking water."'
In addition, I go over the major types of variables found in an experiment. These variables include the independent variable, dependent variable, and control or constant variables.

In the experiment walking water paper towels are set in cups. In addition, every other cup is empty. Food coloring is added to every other cup. In order to introduce the independent variable, I used two types of water. I used fresh water and salt water.
I then let it sit for several hours.

In order to demonstrate the dependent variable, I measured the amount of water moved to the empty cups.

The control variables are variables that should be kept the same. These include the same cup, the same amount of water, and the same paper towels.

You can remember the variables using
Dependent Responding Y axis
Manipulated Independent X axis

MooMooMath and Science create Math and Science videos every day.

Check out the YouTube channel here

Best Symbiosis videos found on YouTube

Check out these symbiosis videos found on YouTube. I have watched each one and feel these are the best. If you additional suggestions then please leave a link in the comments below.

This video by Untamed Science is great because of the video footage. Each type of symbiosis has a real-world example and video footage. The video is closing in 1 million views.

This video by Mark Drollinger includes very clear descriptions of the different types of symbiosis. It is a cartoon style video and would be great for elementary children.

Types of symbiosis
This video is a combination of video footage and cartoon animation. The video gives several examples of each type of symbiosis.

Amazing Symbiosis: Ant Army Defends Tree | National Geographic
Amazing footage and an interesting story, good information. The people at National Geographic are very good at this.

Extreme Animal Relationships | Earth Unplugged
This video by the BBC is very interesting and does show some extreme relationships among animals. The portion of the video covering parasitism is really good.

The Ocean's Symbiotic Relationships
Although this video does not have a huge number of views I felt is was educational and entertaining.

MooMooMath and Science create Math and Science videos every day.
Check out the  YouTube channel here

Top 10 Science Experiments found on YouTube

Saturday, February 23, 2019
Science experiments can be really fun. Easy Science experiments that almost anyone can complete are even more fun. Check out these videos of easy, fun, Science experiments.

This video has some great experiments with simple objects found around your house. In one experiment a paperclip is straightened out and folds back just by placing the paperclip in water.  This video has over two million views because it is very entertaining.

2 easy science experiments

I included this video because the demonstrations are easy but interesting. The first experiment involves passing a chopstick through a balloon, and the second experiment is creating invisible ink with a lemon. This video is nice because it gives step by step directions.

I like this video because it gives good directions, the experiments are fun, and you can probably find every item you need at your house. 

This video has over 7 million views. The reason is that the experiments are simple, and the directions are very clear. This video is well done and educational. Enjoy

This video by 5 minutes crafts is great. I really like it because it includes one of my favorite labs I have my students complete and only involves starch and water. Watch the video, grab some corn starch and water, and have some fun.

This video has an amazing 87 million views. It falls somewhere between hacks and experiments and each demonstration involves matches. It really is a fun video.

Everyone loves balloons and this video gives you 5 easy demonstrations or experiments that you can complete with balloons. I feel this video will inspire you to try a couple of these experiments.

I choose this video by Whizkid science because almost every house has eggs and it will inspire you to start experimenting and learn something. These 5 egg experiments should inspire a child to play around with eggs.

I included this video for the experiment in which a picture is shredded. Each time the picture is shredded a duplicate is created. Check it out, it is fun.

Learn how to create a light bulb with just pencil lead, batteries, and a glass jar. Most people can find these objects at home and using the directions in this video anyone can create a lightbulb.

Coding from Transcription to Translation |DNA to mRNA to tRNA|

Friday, February 22, 2019

Practice coding from DNA to mRNA to tRNA to the Amino acid

Let’s talk about decoding from DNA to mRNA to tRNA to an amino
acid in simple terms.
 DNA is made up of four nitrogen bases, 
Adenine Cytosine, Guanine, and Thymine. Let's shorten this to  A C G and T.
 A always pairs with T and G pairs with C.
If we have this strand of DNA and move from 5 to 3 for the complementary
strand you will have A will pair with T, G with C.  This template strand is moving from 3 prime to 5 prime. Why do you have a 5 and 3 prime end? The phosphate group is attached to the 5' carbon of the sugar ring, which is why it is called the 5' end and the hydroxyl group is attached to the 3' carbon of the sugar ring, which is why it is called the 3' end.
Messenger RNA is similar to DNA but instead of the nitrogen base thymine you have uracil For this complementary strand the DNA has unzipped and you are left with this
strand of DNA which is used as a template for mRNA.  The  T will pair
with the A, the A with the U, the C with G and so forth. Remember A pairs with Uracil instead of  Thymine with mRNA.This step is part of transcription.
Now transfer RNA pairs with the messenger RNA. The messenger RNA will be
the codon and the transport RNA will be the anticodon. The transfer RNA has
uracil, therefore, A will pair with U.
U will pair with A and G with C and so forth. This takes place outside the nucleus and is part of translation. Now let's find the amino acid. You can use an amino acid chart, I'm
using an mRNA chart so I will use the messenger RNA codon. The mRNA will code
in triplets. Notice you are reading from 5 prime to 3 prime.

  • AUG pairs up with the methionine
  • CCU pairs up with prolene
  • CUA pairs up with leucine 
  • GUA pairs up with valine. 

DNA           ATG     CCT  CTA  GTA
mRNA        UAC     GGA GAU CAU     
tRNA          AUG     CCU CUA  GUA 

Amino Acid  met     pro    leu     val

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