Equivalent Decimals

Hi Grade 5s,

Today we talked about equivalent decimals. 

Remember: equivalent means equal.  If we're looking for equivalent decimals, we're looking for decimals that represent the same amount.

We looked at grids made up of 100 little squares in our text books today.  We saw that if, for example, 70 of the squares were coloured in, we could make the fraction 70/100.  We remembered from yesterday that we could turn 70/100 into a fraction: 0.70.

We noticed that we could count the squares on the grid by 1s, but we also noticed that the grid was made up of 10 rows of 10 (making 100).  If 70 squares were coloured in, we could also say that 7 rows of the 10 rows were coloured in.  We could turn that into a fraction, too: 7 out of 10 rows were coloured in, so the fraction is 7/10.  We can make this into a decimal, too: 0.7.

So...0.70 and 0.7 are equivalent decimals, because they represent the same number of squares coloured in our grid.

Hope that helps!

-Ms. Lewis.

Decimals

Hi Grade 5s,


We began our unit on decimals today. We learned that decimals represent part of a whole number and we found examples of decimals we use everyday, like in money and in measuring with rulers.
When we talk about money, we talk about dollars and cents. We discovered that "cent" means 100--we need 100 cents to make a dollar (just like we need 100 years to make a century). We realised that $1.23 is a decimal number, and we can talk about it in different ways:

1 dollar and 23 cents

1 whole dollar and 23 cents towards another whole dollar

1.23

1 and 23/100 (one and twenty-three hundredths: another way to write a fraction--imagine the 23 is above the 100)
We then looked at a ruler. If we were asked to measure 5.4 cm, we know that the 5 represents 5 whole centimetres, and the .4 represents 4 milimetres. We need 10 milimetres to make 1 whole centimetre. We can talk about this decimal number in different ways, too:
5 centimetres and 4 milimetres
5 whole centimetres and 4 milimetres towards another whole centimetre
5.4
5 and 4/10 (five and four tenths)

We also practised drawing decimal numbers using base ten blocks. We began by using a hundreds flat to equal 1 whole. Because we need 10 tens rods to make a whole, the rods represent tenths. We need 100 unit cubes to make a whole, so the unit cubes represent hundredths.

Here's how we can show 4.62:

4 and 62/100 (four and sixty-two hundredths)

Questions?  Post them here.

-Ms. Lewis.

Geometry Test

TGIF, Grade 5s!


Today, I gave you your study sheets for Tuesday's test on our recent geometry unit. Here's what the study sheet said:

We will be having a test on what we’ve been learning about whole numbers. Our test will be on Tuesday, November 24th.

Make sure you know how to:
• name triangles based on the length of their sides (e.g., equilateral, isosceles, scalene)
• name triangles based on their angles (e.g., right angle triangle, obtuse triangle, acute triangle)
• measure the angles of triangles with the use of a protractor
• draw an angle when given a measure (e.g., draw a 45° angle)
• construct a triangle given measurements of sides and/or angles (e.g., construct triangle ABC, with angle A measuring 25°, angle B measuring 80°, and the length of AB measuring 42mm)
• recognize which net creates which 3D solid
• create a net for a 3D solid (e.g., make a net for a triangular prism)

Are YOU ready?
Have a great weekend!

-Ms. Lewis.

Constructing Nets

Hi Grade 5s,

Today in class we talked about nets.  Remember that to create a net, we need to find out how many faces a figure has, and what shape those faces are.

For example, I could make a net of this pentagonal prism:

First, I would count the faces and find that there are 7 faces (2 bases, 5 faces around).  5 of those faces are rectangles, and the other two faces are pentagons.

The net would look this this:

Find a solid figure around your house.  See if you can figure out how you could create it with a net.  Prize tomorrow for whoever posts their net here first.

Yay nets!

-Ms. Lewis.

Naming and Sorting Polygons by Angles

Happy Monday!


Today in class we began to talk about how to name triangles based on their angles.  We remembered that:

• right angles are 90°
• acute angles are less than 90°
• obtuse angles are greater than 90°

We learned that we can measure the three angles (tri-angle...remember?) of a triangle to determine whether it is a right angle triangle, an acute angle triangle, or an obtuse angle triangle.  The rule is:

• right angle triangles have one 90° angle
• acute angle triangles have all 3 angles less than 90°
• obtuse angle triangles have one angle greater than 90°

Remember: you can only have an acute triangle if all 3 angles are less than 90°.

Regular polygons are polygons (closed shape, at least 3 sides) that have all sides the same length, and all equal angles.  Irregular polygons have sides of different lengths, and different angles.

SUPER TERRIFIC BRAIN-BUSTING QUESTION:

WHAT KIND OF TRIANGLE IS A REGULAR POLYGON?  EXPLAIN YOUR ANSWER!
(First person to post the answer on the blog wins a prize in class tomorrow!)

See you tomorrow!

-Ms. Lewis.

Measuring Angles

Hi Grade 5s,

Today we began measuring angles using protractors.  Don't worry if you're still trying to get the hang of it--it takes practice and patience.

I found a great interactive activity at mathisfun.com where you can use a virtual protractor to measure angles. 

Try it out!

http://www.mathsisfun.com/geometry/protractor-using.html

-Ms. Lewis.

Geometry Definitions

Hi Grade 5s,

For homework tonight, you had to find the definitions for the following geometry terms:

• equilateral triangle
• isosceles triangle
• scalene triangle
• pentagon
• hexagon
• octagon
• parallelogram
• trapezoid

 

You can post your definitions straight to the blog as a comment, if you like. Just remember to include your name.

 

See you tomorrow!

-Ms. Lewis

 

Triangles, Triangles, Triangles!

Today, we began our geometry unit by looking at the 3 different kinds of triangles: equilateral, isosceles, and scalene.
Let's take a closer look at each:

Equilateral - We recognized that the word "equilateral" sounds a lot like "equal", which means the same. We are so smart that we figured out that an equilateral triangle is a triangle with all 3 sides the same length.

Isosceles (eye-saw-so-leez) - We learned that an isosceles triangle is one with two sides that are the same length.

Scalene (skay-leen) - We figured that if an equilateral had 3 sides of the same length, and an isosceles had 2 sides of the same length, then a scalene triangle must have 3 sides of different lengths.

We're so smart...
See you tomorrow!

You Survived!

PHEW!

Grade 5s, your test is OVER!  Give yourselves a big pat on the back for the hard preparation work you did to get ready for our test.

I am so proud of how far you have come in this unit.  When we began whole numbers, most of you didn't know how to multiply with two-digit numbers or how to do long division.  Even though it was a challenge, you stuck with it.

Way to go!

I hope you have a great day tomorrow, and remember to be safe this weekend.

See you Monday!

-Ms. Lewis.

Whole Numbers Test

Happy Monday, Grade 5s!

 

Your Whole Numbers test will be this Thursday, October 29th. Today in class I gave you a study guide. Here's what it said:

 

 Make sure you know how to:

• write numbers in standard form and expanded form (e.g., 860 437 is standard form, 800 000+60 000+400+30+7 is expanded form)
• write the value of an underlined digit (e.g., 860 437=60 000)
• write a series of numbers in order from greatest to least/least to greatest
• find the sum of a 3-number, 4-digit addition problem (e.g., 4527+6589+4582)
• find the difference of a 4-digit subtraction problem (e.g., 7412-4386)
• write the related facts for sets of numbers (e.g., 8, 12, 96 = 8x12=96, 12x8=96, 96÷ 8=12, 96÷ 12=8)
• find the product or quotient of multiplication and division problems, including multiples of 10 (e.g., 50x90=4500, because 5x9=45 plus two zeroes)
• multiply using two-digit numbers
• divide using long division

 

If you're not sure about any of these things, post your questions here, or ask Ms. Lewis in class before Thursday.

See you tomorrow!

 

-Ms. Lewis.

 

Long Division

Happy Wednesday!

We've been practising our long division skills for the past few days.  I can tell that each day, you're starting to get it a little bit more and more.  That's great!

Remember the steps:

1. Divide
2. Multiply
3. Subtract
4. Bring down
5. Repeat steps 1-4.

Here's a website with a detailed explination:
http://argyll.epsb.ca/jreed/extras/longdiv/

Questions with tonight's homework?  Post them here!

-Ms. Lewis.

Super Multiplication Challenge!

Hi Grade 5s, and happy Friday!

As promised, here is your SUPER MULTIPLICATION CHALLENGE!!!!!!

65983 x 47324

We are still waiting for the right answer on this one.  First one to post it ON THE BLOG wins a prize.

Who will it be? 

Multiplying with Multiples of 10

TGIF, Grade 5s!

Today in class we looked at patterns formed when multiplying multiples of 10.  We know a number is a multiple of 10 when it ends with a 0.

We started the lesson by finding the products for the following questions:
25 x 10 = ?
25 x 100 = ?
25 x 1000 = ?

Then we used the knowledge we got from the pattern to figure out what 25 x 100,000 would be.

We figured out that the pattern was to add as many zeroes as we see in the problem.  For example, 25 x 10 contains 1 zero, so the answer is 250.  25 x 100 has 2 zeroes, so the answer is 2 500.  25 x 1000 has 3 zeroes, so the answer is 25 000, etc.

We realised we could do the same thing with basic facts and place-value patterns:

7 x 8 = 56
7 x 80 = 560
7 x 800 = 5600
7 x 8000 = 56 000

I hope you have a great Thanksgiving weekend with your families.  Remember: Tuesday is Picture Day.  Better start planning those outfits now!  Maybe something like this?

See you Tuesday!

-Ms. Lewis.

Multiplication and Division Facts to 144

Happy Thursday!

Today in class we reviewed the idea of related facts.  We knew that if 8 x 9=72, then 9 x 8=72, as well.  Based on that, we also know that 72 ÷ 9=8, so 72 ÷ 8 must equal 9.

We say the related facts for 72, 9, and 8 are:

9 x 8 = 72
8 x 9 = 72
72 ÷ 9 = 8
72 ÷ 8 = 9

We also discussed that knowing some multiplication facts can help us figure out ones we don't.  For example, knowing that 11 x 9 = 99 helps us figure out 12 x 9.  We know that if we're multiplying by 12, we can simply add another 9 to the product of 11 x 9 (11 x 9 = 99 + 9 = 108). 

So...12 x 9 = 108.

Questions?  Post them here.

-Ms. Lewis.

Subtracting 4-Digit Numbers

Hi Grade 5s!

Our lesson today began with the question about Emma's pedometer.  We knew that she recorded how many steps she took in 2 hours.  We also knew that she took 1347 steps in the first hour, and 984 steps in the second hour.  We had to figure out how many more steps she took in the first hour than in the first.

We decided that we were looking for the difference, and we learned that the word difference means we need to be subtracting.

So we did: 1347-984.

We started in the ones column, subtracting 4 from 7 to get 3.

Then we subtracted the tens column.  We knew we couldn't do 4-8, so we borrowed from the hundreds column to make the 4 into 14.  Then we did 14-8=6.

Next, we subtracted the hundreds column.  Because we had borrowed from the hundreds column for the tens column, we needed to do 2-9.  We knew we couldn't do that, though, so we borrowed from the thousands column to make it 12-9, giving us 3. 

We had nothing left in the thousands column.

Our answer was 363.  Micah and Lisa wrote:

 Emma took more steps in the first hour. 

Emma took 363 more steps.

We also checked our answer with a calculator to make sure that it was correct. 

So 1347-984=363.

Great job, ladies!

Questions?  Post them here, or ask me tomorrow in class.

-Ms. Lewis.

Adding and Subtracting Big Numbers

Happy Tuesday, Grade 5s!

Today in class, we talked about strategies for doing "mental math" with big numbers.  We spent most of our time talking about rounding numbers to the nearest hundred, and then adding or subtracting them.

For example:

If I needed to subtract 5793 from 8452 (8452-5793), I could round both numbers to the nearest hundred. 

Let's start with 8452.  To round to the nearest hundred, I'm going to look at the digit in the TENS column.  If that digit is 5 or greater, I will round UP.  If the digit in the tens column is less than 5, I will round DOWN. 

The digit is 5, so we will round up to 8500.

Now let's look at 5793.  I need to look at the number in the tens column, which is a 9.  I know I need to round UP to 5800.

Now I can subtract: 8500-5800=2700.


Super Challenge:

Try this to challenge yourself:

75426341+42568772

The first person to post the answer on the blog wins a prize tomorrow in class!

Good luck!

Remember, if you have any questions about tonight's homework, or today's lesson, post them here and I'll write you back.

See you tomorrow!

-Ms. Lewis.

Welcome!

Hi Grade 5s!

Welcome to your math blog!  You'll find homework help and website suggestions here, as well as some other tricks I have up my sleeve :).

Please spend some time looking around our blog site to become familiar with the space.  Leave a message, if you feel brave!

See you tomorrow, and thanks again for a GREAT first math class. 

-Ms. Lewis.