# 2D and 3D Shapes

We have recently been learning about shape in our maths lessons.

The world around us is made up of space and shape and these are very important concepts for students to understand.

We used Jenny Eather’s Maths Dictionary for Kids a lot to learn and revise vocabulary such as:

• 3D shape
• 2D shape
• prism
• pyramid
• vertices
• edge
• face

We have enjoyed drawing and labelling shapes, making 3D shapes with nets, counting edges, faces and vertices and playing a range of games to learn about shapes.

If you would like to try some more activities about shape, you can find a collection of games on the Woodlands site here.

Shapes are all around us! What 3D shapes can you see in this photograph?

Geometry for Dummies – Attribution CC BY-SA 2.0
http://www.flickr.com/photos/thomasclaveirole/538797534/lightbox/

# Perimeter

We have been learning about perimeter in class this week.

Perimeter is the distance around the outside of a shape.

For example, here is how you might calculate the perimeter of our current class novel, The One and Only Ivan.

19cm + 19cm + 12cm + 12cm = 62cm

OR

(19cm + 12cm) x 2 = 62cm

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We have been focussing on:

• Understanding what perimeter is
• Identifying when you might need to know the perimeter of something
• Measuring accurately
• Deciding the appropriate unit of measurement to use
• Using efficient addition skills to calculate the perimeter.

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Yesterday in class students worked in pairs to calculate the perimeter of some objects in the classroom. We then shared our work to compare our results.

Today we calculated the perimeter of some outdoor objects, including the basketball court, sandpit, rock climbing wall boundary and the new downball court.

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# Learning About Fractions

We have been learning about fractions in Maths for the past three weeks.

Our learning intentions focussed on:

• Understanding numerators and denominators
• Using and understanding a fraction wall
• Identifying and naming a variety of fractions
• Putting fractions on a number line
• Comparing fractions and identifying fractions that are greater than/less than other fractions
• Recognising equivalent fractions
• Understanding mixed fractions
• Identifying fractions in a collection of objects
• Using fractions in problem solving
• Identifying the decimals and percentages of common fractions

Here are some fractions websites for you to practise your skills

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# Multiplication and Arrays

In Maths we have been focussing on times tables and the multiplication process.

Multiplication is a very important part of maths, and having a good “automatic recall” of times tables helps us with many different areas of maths.

During class time we have been spending time practising different times tables and using multiplication in our problem solving.

Here are two fun multiplication websites you might enjoy using to practise your skills.

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We have also been working with arrays to help build our mathematical skills. An array is a set of objects arranged in rows and columns. Each row has the same number of objects, so they represent equal groups.  Arrays can make counting and calculating easier. Thanks to Mr Salsich for this array diagram.

Arrays are useful for skip counting and solving multiplication problems.

The array above has 3 rows of 4 blocks. That is 3 groups of 4, or 3 x 4.

We can find out how many blocks there are by skip counting by 4’s:  4, 8, 12 – or by doing repeated addition: 4 + 4 + 4 = 12.

There are 12 blocks. So, 3 x 4 = 12.

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In 4KJ, we have been building our skills to work with bigger arrays. We have been using the two arrays below in our maths lessons this week. The students had to use their mathematical knowledge to calculate how many dots were in the arrays. It was very interesting to see the many different strategies students used during this task.

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## Challenge: What strategies would you use to work out how many dots are in this array? We’d love to hear from family members too!

(Tip – click on the array to see an enlarged image).

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# Learning About Time

Last week our maths topic was time.

Our learning intentions focussed on:

• Identifying times on analogue and digital clocks
• Recognising times that are important to us
• Using 12 hour and 24 hour time
• Calculating elapsed time.

We used this interactive clock to practise telling the time.

Everyone enjoyed matching the digital and analogue times with these Stop the Clock games.

In this game, players need to match the digital clock with the time displayed.

For one task, students viewed the Geelong to Melbourne VLine train timetable on their netbooks. They had to calculate the elapsed time for distances travelled between a variety of train stations.

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# Our World, Our Numbers Concludes

This is a cross post from the Our World, Our Numbers blog.

Since 25th February, the seven classes participating in Our World, Our Numbers have enjoyed:

• learning about different areas of mathematics from their friends in other countries
• making comparisons and contrasts between their lives and the lives of their blogging buddies
• sharing mathematical knowledge and skills
• using a range of tools to create posts
• engaging in rich conversations through commenting

It is now time to finish up the Our World, Our Numbers project. To conclude this wonderful learning experience, all of the classes have been working collaboratively on a collection of mathematical poems.

Watch the Sliderocket below to see the classes perform:

• The Skip Counting Song (B4, New Zealand)
• Aussie Doubling Ditty (4KM and 4KJ, Australia)
• What is a Million? (Room with a View, England)
• Triangle Trouble (Mr Avery’s Class, Massachusetts, USA)
• Smart (Mrs Yollis’ Class, California, USA)
• Shapes, Shapes, Shapes (Mrs Watson’s Class, Canada)

# Problem Solving with Our Special Visitors

Today we are holding a special event called

This is an afternoon for all the students to show a special person some of the things they have been using their netbook for in class.

We have prepared a problem solving activity for our students to solve with their special person.

We have a toolkit of problem solving strategies that we often use in our maths lessons. Perhaps one of these strategies will help solve today’s problem?

## Today’s Problem: Sealed Solution

This problem is from the NRICH website.

A set of ten cards, each showing one of the digits from 0 to 9, is divided up between five envelopes so that there are two cards in each envelope. The sum of the two numbers inside it is written on each envelope:

What numbers could be inside the “8” envelope?

Note: there is more than one solution.

# Number Sequences and Patterns

Numbers can have interesting patterns. Some of our problem solving strategies can help us figure out the rule of a number pattern or sequence.

There are many different types of number patterns. Just some of the common ones include:

Adding

Eg. 2, 4, 6, 8, 10…

Two is added on to each number.

Subtracting

Eg. 35, 30, 25, 20, 15, 10…

Five is subtracted from each number.

Multiplying

Eg. 2, 6, 18, 54, 162…

Each number is multiplied by three.

Mixed Pattern

Eg. 5, 8, 16, 19, 38, 41

In this pattern, three is added and then the number is multiplied by two. It continues + 3, x 2, + 3, x 2….

### What is the rule for these number patterns? Can you leave a comment with the next three numbers in the sequence?

1.  2, 4, 8, 16, 32 …

2. 98, 90, 82, 74, 66 …

3. 181, 184, 187, 190, 193 …

4. 5, 6, 8, 11, 15, 20 …

5. 10, 12, 24, 26, 52, 54 …

# Addition

We are currently learning about addition in maths.

We use addition in every day life all the time, so it is important to improve our skills in this area of maths. In class we have been focussing on:

– Automatic recall of the addition tens and twenties facts

Doubles and near doubles addition facts

Double doubles (for example, 8+8=16 and 16+16=32)

100 facts (addition equations that equal 100)

Adding to the nearest 10 when solving two digit addition problems

Adding ones, tens and hundreds when solving three digit problems

– Using vertical addition when solving larger equations

– Using a range of efficient addition strategies during problem solving tasks.

We like to use engaging websites to help us develop our mathematical skills. We usually use maths websites on the interactive whiteboard, and sometimes on our netbooks too.

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Here are some addition websites for you to try!

Hit the Button

Snappy Maths

Speed Grid Addition

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# “Our World, Our Numbers” Global Project Update

Everyone in 4KM and 4KJ is enjoying the collaborative global blogging project, Our World, Our Numbers. You can read more about this exciting project here.

We have already learnt so much from our blogging buddies. The topics covered so far have been currency, landmarks and recipes. Head over to the Our World, Our Numbers blog to be a part of the learning!

We have published the post below about food on the Our World, Our Numbers blog. Leave a blog comment here on our class blog, or join in the commenting action on Our World, Our Numbers!

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Recently, when Miss Jordan was doing her grocery shopping at the local supermarket, she investigated the cost of a variety of typical Australian foods. Supermarket prices often change, as each new week brings about a new catalogue with different sales and savings. The presentation below shows the prices she collected last weekend.

### Do you eat any of these foods?

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In Maths, we have been learning about rounding. Rounding numbers means to change numbers to make them easier and more convenient to work with. We round numbers when we use money all the time.

As you may remember from our currency post, Australia’s smallest value of money is the five cent coin. We often need to round prices up or down to the nearest 5c when we’re out shopping. The table below shows some examples.

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