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Students can struggle with variables in computer science by thinking they work like variables in math.
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This activity is designed to help students understand the abstract concept of variables in computer science.
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Additionally, using age and other descriptive variables will help students distinguish between variables in different disciplines.
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When you use x, y, or z it is easy for students to get confused by thinking about variables in the way they’re used in math classes.
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You, the teacher, write lines of code on the board for your class (acting as the computer) to compute.
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This activity is built using Java but can be adapted to whatever language you’re teaching.
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Activity:
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Write the following on the board:
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int age; -
Label a clear container age and place it on a table.
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Explain that this corresponds with creating a space in memory for your new variable.
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Then write:
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age = 15; -
Next, write 15 on a sticky note.
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You can also use index cards or small pieces of paper.
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It is helpful to use sticky-notes because this allows you to copy the variable value to the board where you’ve written age = age + 1;
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Place the sticky note inside a tupperware container labeled age.
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Write:
System.out.println("you have a birthday");
age = age+1; -
Go to the age container
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see 15 and get out sticky note, take it and place over the age variable in the right hand side of equation
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i.e. place it over age on the right hand side of
age = age + 1; -
Emphasize we do right side first then left side of assignment statement if they are stuck in math brain.
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now they see 15 + 1 and they mentally do the math
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Write 16 on a new sticky note
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Go back and replace the sticky note in the container
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So now we have a post-it note with 16 in the age container
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Notes:
- It is helpful to use the variable age, because they’ll be less likely to try to solve it like a math equation.