Pre-Lesson Preparation

Open the Marty the Robot app and build the code, from the teacher guide, into the workspace:

This code will have Marty move a distance until they come up to an obstacle. You will need to have a book or wall to stand upright at the end of each of the lengths that Marty will walk. The code will not need you to know how long the object is that will be compared, Marty will stop when the obstacle is sensed.

Warm-Up

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

Tell learners that they are going to take part in an activity where they will need to compare step sizes to see whose are longest.

This activity will require some open space in the middle of the room or an open area outside. Learners will listen to instructions based upon the size of a step to move in different directions. Tell learners you are going to ask them to move with a step size described by one of the following: baby step, spider step, child step, giant step, and adult step. Alternatively, decide as a group the names of the different sized steps.

1. Ask learners to find a space where they have room around them.

2. Have learners practice taking the steps depending on the adjective. Ask them which step they think should be the shortest and which should be the longest. There is no right answer, but it is good to have all learners follow the same procedure.

3. Call out a step type top the class. Have learners walk with this size of step in different directions.

4. Change the adjective as often as you want,

5. Return together to think about the sizes. Ask which one was easiest to make and which was hardest. Ask if any steps were more tiring than others. Ask why they thought this.

6. Repeat as desired.

The goal is to have learners practice comparing step sizes.

Get Learning

For whole-class learning, prepare a range of straight-edge objects that can be placed alongside each other and compared, first in twos and later in threes.

It would be good to have a range of objects against a baseline, either all with the same starting point or all with the same end. To use Marty with this process, there are two options.

• Have a green card at the start of the object and a red card at the end and have learners count how many steps it takes them to walk the length.
• Use the code that is provided in the teacher guide, which will cause Marty to take much smaller steps and allow for a more accurate comparison.

Below are ideas for preparing progressively more challenging comparison lengths. It is highly likely that learners will know right away which is the longest and shortest from the first setup. It is probable that many learners will know which are longest and shortest from the second setup. It is more unlikely that learners will be able to immediately spot the shortest and longest from the third setup.

Make unifix cubes, cuisenaire rods, combined lego blocks, or some other fixed length tool available to compare against the objects you are using.

First setup.

Second setup.

Third setup.

The videos here showcases Marty walking the length of two objects. The graphic on the screen displays the number of steps they are taking. The idea is that counting the steps will support learners to see which is longer and shorter / longest and shortest.

Time for Practice

Share with learners the activity page that they will work on, either in small groups or individually. The first two pages of the booklet have blank sections. This is so that learners can place objects and either trace them or mark about how big they are on their page. The next two pages have shape pairs where learners have to tick either the shorter or longer of two shapes. The final two pages have three shapes where learners will need to tick the longest or shortest one. You get to decide which pages you want to use.

This activity will require some open space in the middle of the room or an open area outside. Learners will listen to instructions based upon the size of a step to move in different directions. Tell learners you are going to ask them to move with a step size described by one of the following: baby step, spider step, child step, giant step, and adult step. Alternatively, decide as a group the names of the different sized steps.

1. Ask learners to find a space where they have room around them.

2. Have learners practice taking the steps depending on the adjective. Ask them which step they think should be the shortest and which should be the longest. There is no right answer, but it is good to have all learners follow the same procedure.

3. Call out a step type top the class. Have learners walk with this size of step in different directions.

4. Change the adjective as often as you want,

5. Return together to think about the sizes. Ask which one was easiest to make and which was hardest. Ask if any steps were more tiring than others. Ask why they thought this.

6. Repeat as desired.

Cool Down

Bring learners back together to discuss where they were successful with cpmparing lengths.

Suggested questions you might ask:

• Who was able to compare the different shapes like Marty did?
• Who can say which shape is longer or shorter? Can you show me?

If you use a formative assessment strategy, like thumbs up or thumbs down, use that here to get a feel for learner confidence with the topic.

Carry out any end of lesson routines.