Welcome to level 2 ### Welcome to level 2 By the end of this lesson, you can: * Save something in a variable * Create a story or drawing using variables <aside class="notes">Students might have a hard time understanding the concept of a variable. We found that giving the students multiple examples of variables will help them grasp the concept better.</aside>

Problem ### Problem In the previous level you might have come across this problem... <iframe class="fragment" src="/render_code/2?code=print%20Welcome%20to%20the%20restaurant%21%0Aask%20What%20would%20you%20like%20to%20eat%0Aprint%20You%20would%20like%20to%20eat...%20answer%0Aask%20What%20would%20you%20like%20to%20drink%3F%0Aprint%20You%20would%20like%20to%20drink%20...%20answer%0Aprint%20Thank%20you%20for%20ordering%20with%20us%21%0Aprint%20Please%20enjoy%20your%20...%20answer"></iframe> <aside class="notes">Warning: This code doens't work in this level. Don't run the program, just discuss it. Let your students take a look at the program and let them predict the output. Hopefully they will come to the conclusion that the last line will only say 'Enjoy your (drink they ordered)' and that the computer will have forgotten the food. With 'ask' the computer can only remember one item. In this level you will learn to use variables to solve this problem.</aside>

What is a variable? ### What is a variable? A variable is a place in the computer's memory, where it stores the answer to the question. This might sound difficult, but check out the example. <iframe class="fragment" src="/render_code/2?code=answer%20is%20ask%20What%20is%20your%20name%3F%0Aprint%20Hello%20answer"></iframe> <aside class="notes">We use the word variable in computing to describe a place in a computer’s memory where it stores information that changes. The variable is a like a box or container that holds the thing that is changing. The box stays the same but whatever is inside can change or vary. Show the students how the variables work. Point out that the name of the variable `answer` in the last line are replaced with the value of the variable. The blue box that appears in your output screen shows you the variables you've used and what they have been set to.</aside>

The `is` command ### The `is` command To make or 'set' a variable we use the `is` command. The name of the variable comes before the `is` and the `ask` command behind it. We can choose the name of the variable and use something else than `answer`. <iframe class="fragment" src="/render_code/2?code=name%20is%20ask%20What%20is%20your%20name%3F%0Aprint%20Hello%20name"></iframe> <aside class="notes">Ask the students to come up with their own examples.</aside>

Variables ### Variables We can also set a variable without asking a question. The name of the variable comes before the `is` and the value of the variable behind it. <iframe class="fragment" src="/render_code/2?code=food%20is%20hamburger%0Adrink%20is%20water%0Aprint%20I%20would%20like%20to%20eat%20food.%0Aprint%20I%20would%20like%20to%20have%20some%20drink."></iframe> <aside class="notes">Ask students if they could think of another variable (length, shoe size, haircolor etc.) and add your own examples to the code.</aside>

Multiple variables ### Multiple variables Now that we use variables, we can use multiple variables instead of just one `answer`. <iframe class="fragment" src="/render_code/2?code=name%20is%20Hedy%0Aage%20is%2015%0Aprint%20name%20is%20age%20years%20old"></iframe> <aside class="notes"></aside>

Sleep ### Sleep You can also use the `sleep` keyword to pause the code for a while. <iframe class="fragment" src="/render_code/2?code=print%20My%20favorite%20colour%20is...%0Asleep%202%0Aprint%20green%21"></iframe> <aside class="notes">Show the students the 'sleep' keyword. Ask them what they think the 2 stand for. Change the 2 into another number to show that they can decide for how many seconds the code will be paused.</aside>

Sleep 5 ### Sleep 5 You can add a number after the `sleep` keyword if you want the pause to be longer. If you want, you could even use a variable instead of a number to decide the duration of the sleep keyword. <iframe class="fragment" src="/render_code/2?code=pause%20is%2010%0Aprint%20My%20favorite%20colour%20is...%0Asleep%20pause%0Aprint%20green%21"></iframe> <aside class="notes">Show the code and if you want you can even change the 10 to an ask keyword.</aside>

Drawing with variables ### Drawing with variables In level 1 you've learned how to use forward 100. Now you can use a variable too. <iframe class="fragment" src="/render_code/2?code=distance%20is%20ask%20Hwo%20far%20should%20i%20go%3F%0Aforward%20distance"></iframe> <aside class="notes">Show the students that they can use variables with the drawing turtle now too! Run the code multiple times with different answers, to show the use of variables.</aside>

Drawing with degrees ### Drawing with degrees Before you could turn left or turn right, now we can use degrees! <iframe class="fragment" src="/render_code/2?code=forward%20100%0Aturn%2045%0Aforward%20100"></iframe> <aside class="notes">Show the students the code. In the next slide we'll show multiple angles.</aside>

Degrees ### Degrees A full circle is 360 degrees. Half a circle is 180 degrees. A right turn is 90 degrees. A left turn is 270 degrees. You can fill in any number you want. <iframe class="fragment" src="/render_code/2?code=turn%2090%0Aforward%20100"></iframe> <aside class="notes">Make sure the students understand degrees. They may have learned this already in maths, but it might be completely new to them. If the students have never heard of degrees before, it might be nice to show them a degree wheel. You could even print one out for them. Use the example code on the slides to show the students multiple angles.</aside>

Degrees and variables ### Degrees and variables Degrees can be variables too! <iframe class="fragment" src="/render_code/2?code=degrees%20is%20ask%20How%20many%20degrees%20should%20the%20turtle%20turn%3F%0Aturn%20degrees%0Aforward%20100"></iframe> <aside class="notes">Show the students that you can make the amount of degrees a variable as well.</aside>

Debugging ### Debugging Debugging a code means getting rid of mistakes in the code. Let's debug this code together. Click the ladybug button to start the debugger. <iframe class="fragment" src="/render_code/2?code=print%20Welcome%20to%20the%20donut%20shop%21%0Afilling%20is%20What%20kind%20of%20filling%20would%20you%20like%3F%0Aprint%20You%20have%20chosen...%20Filling%21%20Yum%21%0Atopping%20ask%20What%20kind%20of%20topping%20would%20you%20like%3F%0Atopping%20is%20delicious%21%0Aprint%20I%27ll%20go%20get%20your%20donut.%20sleep%0Aprint%20Here%20you%20go%21%20A%20filling%20donut%20with%20toping%21%0Aask%20Have%20a%20nice%20day%21"></iframe> <aside class="notes">Model how to use the debugger and the eye icon.</aside>

Let's review! ### Let's review! What did you learn today? <aside class="notes">Ask the students to list what they've learned today.</aside>

Let's review! ### Let's review! Which adventure did you like best? Why? Which adventure did you like least? Why? <aside class="notes">Ask the students for their opinion.</aside>

Show and tell! ### Show and tell! Would anyone like to show the class a program they've made? <aside class="notes">Let some students show their work to the class.</aside>

Sneak peek into the next level... ### Sneak peek into the next level... In the next level you'll learn how to make a list and let the computer pick a random item of that list! <aside class="notes"></aside>