We've Got the Power!

This week we're SUPER excited to learn about the SUPER Power of Ten! Using exponents is an efficient way to write numbers that have a few too many zeeeeeros.

Here are the vocabulary words for this lesson: 

powers of ten

base number 

exponent

The exponent (or power) tells us how many zeros are in the number when the base number is 10.

The image below has a place for everything with everything in its place. The base can be any whole number, but today we are only focusing on the POWERS of TEN!

The number above really means 10 x 10 x 10 = 1,000.

(exponent of 3 = 3 zeros)

Multiplying with powers of ten is SUPER fun! When multiplying a whole number by a power of ten, just count how many zeros you have and attached that to the whole number! If you use exponents, they'll tell you how many zeros you need. Just ask 'em.

Now for DIVISION...

The video below will explain how to use the power of ten to quickly divide numbers. The SUPER cool thing is that you can do all of this in your head. 

Dividing a number makes it smaller. When dealing with powers of ten, you just move the decimal to calculate your answer. In class today we remembered that a whole number has an invisible decimal on its right.

8.

When you multiply or divide by powers of 10, you just change the location of the decimal point. you can multiply by powers of 10 simply by moving the decimal point to the right the number of places shown by the exponent on the 10 (or the number of zeros in the power of 10, if written out). when dividing, move the decimal point to the left the number of places shown by the power of 10. remember that the decimal point is always located after the ones place, so in the whole number 23, the decimal point is located after the 3 ones.

Games and other resources:

Power of Ten

Khan Academy

OnlineMathLearning.com

The Math Page
Math is Fun 

What's so wonderful about a zero, anyway?

Have a super evening!

Comparing Big Juicy Decimals

If you ask me, 2015 is the perfect year to learn about comparing decimals to the thousandths using <  >  and = symbols. Am I right?

You can compare many things in life, such as cats and mice...

You can also compare numbers.

Before we go any further, let's time travel back to third (or maybe second) grade.

In your younger years you might have learned about alligators who liked to eat numbers. 

BIG numbers.

Remember?

The alligator's big mouth and sharp teeth always opened to the bigger number,

as do the < and >  symbols.

Even though we are big fifth graders, we can continue to use this visual to remember the correct way to write the greater than and less than symbols. I still do and I'm an old lady.

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Now let's talk about comparing crazy-big numbers with multiple digits and decimals! This is actually really fun. You always start with the digit that has the greatest value (the one on the far left). Compare the numbers with the same place values. If they are the same, move to the right until you find numbers that are different.

The numbers above start out the same 452. However, when you get to the tenths column, you notice that the numbers are different . Well, which number is greater (or larger) 7 or 2? 

Soooo...

452.781  >  452.209

(452.781  is greater than  452.209)

Done! Move on!

Check out these examples below. The highlighted digits are the ones we compared to find out which was greater. Notice how they have the same place value? That means they can be compared.

Here are a few helpful resources for this concept...

Comparing and Ordering Decimals 

(movie & info)

Fruit Splat 

(game)

Compare Decimal Numbers 0 to 1 

(lesson & game)

Ordering Decimals 

(interactive decimal sort)

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Check your k-mail for a printable version of the notebook page for this week. You can use the Grip and Rip trick to quickly add it to your spiral. Here is a look at my notebook page. Please make sure your spiral is up to date before next Tuesday's class!

Click on any picture on this blog to enlarge it.

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See you later, alligators.

2-Digit Divisors

Hey!

We moved on to 2-digit divisors this week and you guys are doing great! Before next week's class, make sure your notebook is up to date and that you've taken the 5.NBT.6b Quick Check! If you were absent on Tuesday, k-mail your quick check to me. The printable copy was k-mailed to you.

Speaking of Quick Checks, I thought I'd show you a couple samples of what a "4 point" quiz looks like. Both are easy to read and complete. Click on the images below to enlarge.

Even if you get the answers wrong, you can get points for trying your best and remembering to write your name! If you don't write you name on your slide, I may think you were absent. Eek!

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Here is a look at my notebook pages from Tuesday. If you click on the picture a bigger version will pop up. Feel free to copy down the information, if needed!

Sometimes it helps to have a good old fashioned multiplication table handy. You can use it for long division, finding area, fractions, and of course multiplication. I like this one because it's colorful and easy to use. If you think you might want to use one, you can print it out and glue it to the inside of your math notebook cover.

Click here for cool Multiplication Charts from Guru Parents!

If you would like some extra help with division or you're in the mood for a new math game. Click on the links below!

Long Division Lesson

Long Division Step by Step

Double Digit Study Jams

Math Magician Challenge

Remember to k-mail me if you have questions or need help.

Next up... Geometry!