the power of decimals 1. instructions: 1)read each slide carefully. remember, you are responsible...

The Power of Decimals

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Instructions:1)Read each slide carefully. Remember, you

are responsible for this information!2)If you wish to go back, click the back arrow3)Answer the questions at the end of each

section. This will allow you to move on to the next question

4)Have fun!

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Introduction

Introduction to decimals

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Decimals are used to show PART of a whole number

Partial numbers fall to the right of the DECIMAL POINT 1.5

Whole number

Partial number

Place names

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2.89

The farther right the decimal place, the smaller size.

See labels below

Ones (small)

Hundreths (smallest)Tenths

(smaller)

Fractions and Decimals

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All fractions can be converted into decimals(Some look messier than others.)

Examples

½= 0.5 1/10= 0.1

1/4= 0.25

1/7= 0.14285

2.63Which number is in the hundredths place ?

1.22.33.64.0

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Question 1

Remember: The farther right, the smaller the number

Try again

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Incorrect

Exactly! 3 is the hundredths place. It has the smallest value because it is farthest right

Click here to continue

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Correct!

To put decimals in numerical order:

Work left to right!!Once you find the higher number, stop!

Example

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Ordering decimals

same same

Bigger! Stop!

Smaller! Stop!

Not needed

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Ordering decimals

1. 2.392. 2.483. 2.474. 2.365. 2.43890798698

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Which number is bigger?

Remember, work left to right. Click here to double check the slide.

Try again?

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Incorrect

Exactly. 2.48 is the largest of the numbers

Click here for Question 2

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Correct!

A. 8B. 8.1

C. 8.15D. 8.155

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Which number is smaller?

If no decimal is present, it is the same as zero.

Click here to try again

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Sorry, not quite!

Since the first numbers are the same, 8 is the smallest because it has no decimals

Click here to continue

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Exactly!

Rounding is changing decimals into whole number This helps for easy adding and subtracting estimates Examples:

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Rounding

How do I know which way to round?

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Easy Rule0.5 and above= Round up

0.49 and below= Round down

Why bother rounding?

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Rounding helps make adding and subtracting easier.

Example:3.41+7.82=?3.41 rounds down to 3

7.82 rounds up to 8

3+8=11 (much easier)

Round the numbers in this equation and estimate the answer

2.76+7.11=?A. About 9B. About 10C. About 11D. About 7

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Rounding Practice

-Remember the Easy Rule: 0.5 and above= Round Up

0.49 and below = Round Down

Try Again

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Nope, try again

2.76 rounds up to 3 7.11 rounds down to 7 7+3= about 10!

Click here to continue

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Exactly!

Adding and Subtracting Decimals

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Decimals add together just like whole number.Two things to remember:

1.Make sure the decimals line up2.If no decimal is present in one

number, add a zero

Click to see examples

Adding and Subtracting Examples

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3.45+2.9=?

3.4 5 2.9 +

3 .74

3.45+2.9=?

3.4 5 2.9 0 +

6.35

Adding and Subtracting Examples

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8 - 4.39=?

4.39 8 -

4.31

8 - 4.39= ?

8.00 4.39 -

3.61

What is the sum of 4.38 + 2.8 (use paper and pencil if needed)

A. 7.28B. 6C. 4.66D. 7.18

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Practice!

Try again. Click here if you would like to view the slides again.

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Nice try, bye-bye…

Well done! You lined up the decimals and used a zero when needed.

Click here to continue

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Correct!!

What is the difference of 9.78-5.1=?A. 4.38B. 9.27C. 9.28D. 4.68

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Subtraction practice!

Remember to add zeros when needed.

Click here to try again…

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Nope

Bah, Humbug!

Well done, you have the hang out this

Click here to continue

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You’re doing great!

Metric System

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Decimals help us understand the metric system

Large measurements can be made smaller with decimals

This helps measure smaller items (and people!)

1/100 of a meter (or 0.01)

Good for measuring small distances (like the length of your computer screen)

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Distance Measuring

100 centimeters Good for measuring

long distances (like the distance between countries!

1000 grams Good for measuring

large masses (like an elephant)

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Mass Measuring

1/1000 of a kilogram (or 0.001)

Good for measuring small masses (like this rat)

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Volume Measuring

1000 mililiters Large liquid amounts This bottle is a 2 liter

bottle

1/1000 of a liter (0.001 liters)

Good for small liquids Found in science a lot

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Units

10000.010.001

These can be applied to ANY measurement! (i.e. Kilograms, Centiliters, kiloliters etc)

What would I most likely use to measure the mass of a house?

A.GramsB.LitersC.KilogramsD.Meters

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Quiz time!

Not quite, remember “mili” means 0.001 (smaller)

“Kilo” means 1000 (larger)

Click here to try again!38

Not quite…

Good job, you’re really doing well!

Click here to continue

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Exactly!!!

What would you use liters to measure?

1)The mass of your little brother2)The volume of a swimming pool3)The distance from your house to Central4)The volume of a juice box

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Just two more questions!

Click here to review the slides about volume.

(If you need to look closer at the slides, remember, you can always click the “back” arrow before answering questions.)

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Incorrect

Liters would work for a swimming pool! Liters would not work well for a juice box. Milliliters are smaller and would work a lot

better

Continue!

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You’re right!

You are planning on driving to New York this week. How would you measure the distance to see how much gas you will need? (remember the slide on units)

A. LitersB. CentimetersC. MetersD. Kilometers

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Final Question!

Good guess, it’s a tricky question. Remember that units (Kilo, mili and centi) can apply to ANY type of measuring.

Click here to try again

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Incorrect

A Kilometer is 1000 meters. This would work very well in measuring a long distance!

Continue!

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Exactly!! Good job!

Almost…

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You could use meters to measure the distance, but it’s not the best answer.

Remember, it might be something not covered.

Try again

The End

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Well done! You obviously know your stuff when it comes to decimals and measuring! Good luck on the test, I know you’ll do great!

Click the flag to end the assignment

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Question slide

Click here to try again

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Incorrect

Correct

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Continue!

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Question slide

Click here to try again

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Incorrect

Correct

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Continue!

The End

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