Meet Me on Mars (MMoM)
Lesson Name: 3- Scratch Basics – loops and conditions
Date to be taught:
“I Can” Skills:
Last Time / This Time / Next time- Create and logon to a Scratch account
- Create and position the objects of the simplified solar system (sss) in Scratch / - Create loops for simulating the planet orbits around the sun
- Program event handlers for pausing and continuing the simulation / - Add the rocket and its launch functionality
Before the Lesson:
Copies to Make / Materials to Bring / Visuals to Make- Projector for laptop
- 1 laptop for each student
- Internet connectivity for all laptops
Add Sun, Earth, Mars sprites and orbits:
Add Continue and Pause support (through run variable):
During the Lesson:
Section / Time(min) / I Say / Do / They Say / Do
Teach back / 10 / - Ask the students to demonstrate their work from last week and explain:
o “Green Flag” purpose and action
o Canvas coordinates and planet positioning / - Students show and tell
Mini Lesson / 10 / Figuring out the planet orbits – moving in a circle:
- Ask the students/volunteers to show/demonstrate how they would move in a circle if they were a sprite
o Derive the procedure (“algorithm”) of moving a bit forward (“step”), and turning a bit left (“angle”) – repeatedly!
- Show on the board the effect of a larger step
o Resulting in a larger circle (radius)
- Show on the board the effect of a larger angle
o Resulting in faster movement (speed/rotation) / - Students actually execute the procedure of repeatedly “moving a bit forward (‘step’), and turning a bit left (‘angle’)”
Activity 1 / 15 / Making the planets orbit around the Sun – loops, steps, turns:
- Ask the students to log on to their account and
o Figure out which blocks to use: Green Flag, loop, go, point, move, turn,
o Create an orbit loop for both Earth and Mars
- The orbits don’t have to be accurate, nor do they need to circle exactly around the Sun in the center
- We will learn about tracing the path of the planets with a pen, and then we’ll refine the orbits
- Ask a few volunteers to show/share their programs showing orbiting of the planets / - Students logon and create planet orbits
Mini Lesson / 5 / Tracing the planet paths – pen commands:
- Show the Scratch blocks
o Clear, pen up, pen down, set pen color to / - Students participate in adding the pen tracing functionality
Activity 2 / 10 / Tracing the “realistic” planet paths:
- Ask students to draw
- The step for Mars is 2.8, and the angle is 1
- The step for Earth is 3.5, and the angle is 2 / - Ask students to draw
Mini Lesson / 15 / More about sprites and costumes:
- Show students how they can import a sprite for the planet Mars, and ask them to change their current costume / - Students import and place Mars correctly
Wrap up / Remind students of our goals:
- Create a simplified version of the solar system (just 2 planets)
- Represent a system with correct proportions of distances, but not real proportions of object sizes
- Create a simulation of the system / - Students teach-backs
Thumbnails lesson timeline: