Estimation

ESTIMATION

Estimate is
When you estimate the answer to a problem it means that you give a pretty good guess at what the answer will be.
Example:   199 x 302 = ?      Well, that's close to 200 x 300 which is 60,000. (I can do that in my head).   So, my estimate for the answer is 60,000.  The real answer is 60,098.

Estimation is a very critical skill to learn. You can use estimation in everyday life. Estimation can be used to estimated the cost of a group of things, to estimate the discount off of an item,  Estimate how long it will take to complete a task, How much food you need to feed a group, and you estimate how long an object might be. You could also use estimation to determine how much paint you need to paint a room, and how much money you need for a vacation.

Students sometimes use estimation without even knowing it. They estimate( take a guess) at what score they will receive on a test, how much money they will receive for their birthday, How much money they have in their piggy bank, if they have enough money to buy a certain toy they want, and how many goals they might score in their next soccer game. 

I use estimation while I am working at my job by estimating how many snacks I will need, how long it might take to complete a project, and how long it will take the kids to get all their winter gear on. This is a hard one to estimate, because it depends on many different factors. Some days it might take 5minutes and other days it might take 15 minutes.

Teachers use estimation all the time. Estimating how many pencils you will need for the school year, how many kids might need scholarships to attend a field trip, and how many worksheets might be needed based on how many kids might need a second one.

PBS kids has many games on estimation

http://pbskids.org/games/estimation.html

PBS kids Sid The Science Kid Estimation  Investigation

Multiplying numbers

What is Multiplication?

Multiplication- is a mathematical operation of multiplying 2 or more numbers called factors. The answer is the product.

 

There are many different ways kids are taught to multiply numbers such as: groups of, multiplying using an array, and by breaking apart the number into smaller numbers that you already know the answer to and then adding them.

Multiplying using groups of also know as the commutative property of multiplication.

If I have 12 pennies I could divide them in to 2 groups of 6, or 3 groups of 4. The number of groups goes in the first spot then the number in each group goes in the second spot so 2 X 6 = 12 and
3 X 4 = 12

It is important for students to understand these different methods of  multiplication. Most people prefer one method over the other. Everyone is different, and it is alright to change your preferred method of multiplication many times or as you grow up a further understand the many different ways to multiply numbers to get the answer.

Multiplying using arrays

Multiplying using arrays is like I have 5 rows and 4 columns.
X X X X
X X X X
X X X X
X X X X
X X X X

Here is an activity you can use to help you understand multiplication using arrays.
http://www.haelmedia.com/OnlineActivities_txh/mc_txh3_002.html

Multiplication song from School House Rock

Here is a video about multiplication