Task learners to draw a picture that has multiple straight lines and right-angle corners. Challenge them to create at least 8 of each in their drawing, and either label it or use a color to indicate which angle they have drawn.

Encourage learners to model each of the photos of Marty from the activity page. Letting learners experience how Marty looks will help them to decide how much of a turn has been made between the two arms.

For learners still a bit puzzled by some of the examples, show how you can move either your own arms and maintain the angle of turn or do so with Marty with the following code block. (There is a step-by-step guide in the teacher guide document to make this.)

Teacher Guide

What is and Angle

Presentation for What is an Angle

Introduce learners to 0, 90 and 180° angles. Use Marty's arm to illustrate an angle. Change the degrees of one arm to model how 0, 90 and 180° angles can look. Identify drawn angles as being either 0, 90 and 180° angles.

Open the Marty the Robot app and build the following two pieces of code into the workspace:

This is for the Marty Angle Warm-up (in the time for practice section)

This is to have Marty display a range of 0, 90 and 180° angles in the time for practice section

Save each of these pieces of code in the app and give them appropriate names. Please consult the teacher guide for step-by-step instructions for building them.

Share with learners the objectives and success criteria for the day's lesson, from slide 2 of the presentation in the educator resource section; perhaps display this before the lesson starts and keep it displayed until another slide is needed. 

Warm up the class by modeling a variety of angles, with your left and right arms. You need to turn to the side so that learners see either your left or right side, in profile. 

We are going to start with some angle exercises: we are going to use our two arms and make an angle by holding both our arms out, straight in front, and moving one of them to point above our heads. The angle is how much one of my arms has turned at my shoulder; that is a measurement called an angle. Today we will create different angles and then you will get a look at some angles with Marty the Robot."

Bring both arms straight in front. Follow this with one arm directly in front and the other directly behind. 

As you model the angle, ask learners to copy what you do. For this lesson, keep to 0°, 90° and 180°, mixing them up to give learners a baseline for comparison; slowly go from one to the next to illustrate that the angle is the amount of turn. Keep one or the other arm straight ahead while exercising at this stage of the lesson. Swap arms to show that either one can be pointing straight ahead, and an angle is still created. Ask learners if anyone would like to have an opportunity to lead others in the class. Continue this until everyone seems 'warmed up',

Revisit the demonstrated angles, giving each a name: 90° angle or right angle, 180° angle or straight angle and 0°. Here are some ideas for information you could share.

"we use degrees to measure the size of an angle"

"we call the parts that make an angle arms"

"our shoulder is where the vertex of the angle is, the vertex is where the two arms of an angle meet"

"as I turn my arm one way at the shoulder, the angle increases"

move your arms between 0 and 90°, to show the increase and decrease in the turn, and have learners copy you

"90° is when our arms are pointing in different directions like the corner of a book, but not opposite directions, and we call it a right angle"

repeat this process decreasing the angle from 90 to 0

"as I turn my arm the other way at the shoulder, the angle decreases"

extend your arms so that one arm is pointing directly forward while the other directly back

"180° is when our arms are pointing in opposite directions, like the edge of a table, it is a straight line and we call it a straight angle"

Challenge learners to show you other parts of their body they can use to model the different angles, this may require them to lie on the ground and use their legs. Alternatively, ask them to show you, with their arms, vertically when you display your arm horizontally. This needn't be required for all learners: some may need the security of copying what you are doing.

Present Marty to the class as an expert angle maker. Inform learners that Marty loves to make angles with his two arms, just like we did with our two arms. Turn Marty to the side so that learners can see the arm joint at Marty's shoulder. Run the code block that has Marty move from 0° to 135° and back through 0° to -135° and back to 0°. These are the suggested limits on Marty's rotational movements. Alternatively, show slide 3 from the presentation for the angle warm up.

Tell learners that Marty is now warmed-up and ready to show some angles. Ask learners to see if they can copy Marty: 

press the green flag on the MartyBlocks program you created

move Marty's left arm to a position in front of them, to make a positive angle

press one of the three blocks that controls Marty's right arm: to make a 0, 90 or 180° angle

ask learners to copy the movement and ask them what angle that feels like: 0, 90 or 180°

In order to use the -180° block, you need to move Marty's arm at least 45° forward of 0°. This is because Marty's range of movement is from -135 to 135°.

Repeat this process until you feel they are confident displaying these three base angles. 

Ask individual learners to model an angle, either 0, 90 or 180°. Move Marty's left arm to copy the greatest positive angle of the display and press the block of code that will create the angle the learner has modeled. Ask the class if they think Marty has done a good job. Have them copy the initial learner and choose a new volunteer.

Share with learners the practice activity in the workbook, in the resources section, that shows a collection of Martys creating angles with their two arms. Learners can choose how they want to indicate the value of the angle, either writing 0, 90 and 180°, drawing lines to connect equivalent angles, or something else that you use with your class. The first three examples have rays drawn over Martys arms - the arms of the angle - share with learners that doing this may better support seeing the size of the angle compared with just using the photo of Marty. 

The second part of the activity sheet challenges learners to look for examples in their environment where they can see examples of arms that create 90 and 180° angles. Some examples may include table surfaces, corners (room, books, desks, window frames), monitor edges. Celebrate these examples and challenge them to think of more obscure ones or ones that they cannot see just now but can picture in their heads.

Bring learners back together to discuss the challenges they faced and overcame. Have learners share any strategies they used to identify which angle Marty's arms created. If confident, have learners model some of the example questions and say what angle they created.

What were some interesting places where you found a 90° angle?

Were all the angles you discovered flat on the ground or a table? Were some angles up the way, like on a wall? Were there different ways you saw angles displayed?

A device with MartyBlocks to show the angles in action

Workbook for What is an Angle

Using Marty to bring degrees to life

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Mathematics - Upper Years - Lesson 1 - What is an Angle

Challenge learners to complete the extension activity linking an analog clock to an angle. The extension activity displays a range of digital clock times, which learners need to draw on an analog clock face and categorize as either acute, obtuse, or right angles. The only right angles are 9:00 and 3:00 to avoid confusion with the minute hand moving as the hour progresses.

Learners could draw the clock hands or picture them in their heads, but they need to order the angles from least to greatest and label them as acute or obtuse.

For learners still a bit puzzled by some of the examples, show how you can move either your own arms and maintain the angle of turn or do so with Marty with the code block detailed in the teacher guide.

Teacher guide

Presentation for Comparing Angles

I can identify an angle as acute or obtuse.

Begin to compare angles in terms of size: how can we tell which angle is bigger or smaller than another? Extend learners' awareness of angles to include categories like acute and obtuse.

Open the Marty the Robot app and build the following piece of code into the workspace:

This code will create an angle with Marty's arms, hold the angle for 5 seconds and create another one.

Save this code in the app and give it an appropriate name. Please consult the teacher guide for step-by-step instructions for building it.

If you can, take learners outside to find angles in their environment. Remind learners that an angle is where one arm turns away from another at a vertex. Illustrate with your arms held out in front and moving one of them up or down, at the shoulder, while keeping the other straight. Feel free to substii

If going outside isn't an option, there are examples of tree angles in the presentation on slide 3. If you go outside, feel free to not use this slide.

Encourage learners to see if they can spot examples where two arms meet at a vertex and form an angle. If the examples are able to be easily moved, collect them together for later comparison. If the resources are available, use devices to photograph the found angles for later comparison or take out notebooks to sketch the discovered angles.

The reason for using natural objects for angle discovery is because of the tendency to have mainly 90° angles in a built environment.

If you were able to, collect the natural examples of angles and present them with the same orientation: one arm of the angle is a continuous line. The image below shows a possible arrangement. If you were unable to go outside, slide 3 of the presentation shows the collection of angles, pictured below but they can be moved about when not in presentation mode.

If you were not able to collect the natural angles, but were able to take photos or sketches, display these examples in an open area in the classroom to compare the various angle sizes. Have a group discovery where together you order the created angles from least to greatest or vice versa.

Here are some ideas for information you could share and questions you could ask.

"what do you look at to decide which angle is more?"

"what is the part of the angle called where the two arms meet?"

"because the turn is more for the arms of these sticks - point to those sticks - the angle is greater" and vice versa for sticks with a smaller angle.

It would be best to have a range of angles from small acute to big obtuse.

e have seen angles that are 90°, which are called right angles and 180°, which are called straight angles. There are lots of angles that are between them and angles that are less than 90°. We have names for them." 

Display the last slide of the presentation to show the definitions for acute and obtuse. Have learners think of items in their lives that could be described with the provided definitions. The presentation displays a sharpened pencil as having an acute angle, and a dull pencil as having an obtuse one. 

Take the organised angles, either from the presentation, sketches or from what was gathered and arrange them into one of the two groups: acute or obtuse angles. Draw attention to any angles that were found that were straight or right. Ask learners what they think they should do with them. Draw attention back to the definition:

neither 90° and 180° angles meet this criteria; they will need their own category: right or straight angles

Challenge learners to reproduce each of the angles being using their arms, with their shoulders being the vertex. Model this for learners first:

Turn to the side so that learners will see your shoulder. 

Move one arm out in front of yourself to be the starting arm

Slowly move the other arm to the position so that it is similar to one of the sticks either pictured on-screen or displayed on the ground. Speak as you are moving the arm away from 0 degrees to verbalise how big it is getting or act in surprise at how small it is because it didn't take long to move the second arm from the first.

 lesson, remind learners that Marty is an expert angle maker; if you haven't had the opportunity, introduce Marty with this skill. Inform learners that Marty is very skilled at making angles of all sizes and would like to help the class get more confident at comparing the size of angles. There is a small script to get Marty warmed up for displaying angles in the teacher guide.

Tell learners that they need to get a partner. One person will copy Marty's first angle and one person will copy Marty's second angle. Using the longer program that you set up prior to the lesson:

Marty will move the right and left arm to create an angle

Learners need to decide which angle is greater or less

Repeat this process until you feel learners are quickly able to identify the greater/lesser of the two angles. If there is a group of three, press the green flag a second time and then press the stop button after Marty creates the first angle. 

Share with learners the practice activity in the workbook, in the resources section, that shows a collection of Martys creating angles with their two arms. For each question, learners need to identify which angle is the greater or lesser of the two. On the page, some of the initial Martys have angle arms over Marty's arms. Encourage learners to indicate this on their pages to better identify where the angle is.

The second part of the activity sheet challenges learners to: think about the angle created by several objects in the environment, make a sketch of the angle they think it would be, organise the sketches in terms of angle size: acute or obtuse.

Bring learners back together to discuss the challenges they faced and overcame. Have learners share any strategies they used to identify which angle was greater from what Marty displayed. If confident, have learners model some of the example questions and say what angle they thought about when completing the activity.

What is a good way to describe an acute angle?

What is a good way to describe an obtuse angle?

How did you compare the angles when the arms pointed in different directions?

Workbook for Comparing Angles

Extension Activity for Comparing Angles

Use Marty to compare to angles, in terms of size

Mathematics - Upper Years - Lesson 2 - Comparing Angles

This pack has two lessons introducing angles to learners. The first lesson introduces angles as a measurement of the turn between a first and second arm and describes 0, 90 and 180° angles. The second tasks learners with comparing angles and classifying them as obtuse or acute.

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Mathematics Lesson Pack - Upper Years - Angles

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