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MakeCode Arcade Precision Activities

The following MakeCode Arcade programs can help you see approximation and overflow errors in action.

Floating Point and Overflow

Floating Pt and Overflow

Click on Edit Code to open the program.

When you run this program, it is dividing 17 by 5 and displaying the result.

  1. Replace the 17 with 3.4. What is the calculation now?
  2. Perform the same calculation on a calculator. What is the answer?
  3. Why do you think they are different?
  4. Replace 3.4 with it with 0.00000000001. What is the calculation now?
  5. Now, change the calculation to a multiplication rather than division

Select multiplication
Select multiplication

Once you change to multiplication change the number to calculate a large number. Keep changing the numbers until it reaches overflow.

  1. Now try using the myint and myfloat variables in your calculation. Hint - look in the Variables Toolbox drawer

myint and myfloat variables
myint and myfloat variables

Is the result an integer or a floating point number?

  1. From the Info Toolbox drawer, pull out a Set Score block and place after the mySprite Say block. From the Text Toolbox drawer, pull out a Parse to Number block and place in the Set Score block. In the Parse to Number block type "7.5e2".

set score block
set score block

What happpens?

Approximation

Approximation

Click on Edit Code to open the program.

  1. What is the value of x?

  2. What is the value of y?

  3. According to the algorithm, is the program correct, when it displays "False"?

  4. Why or why not? What is going on? Hint: move the mySprite say block

say x = y block
say x = y block

out of the source code and replace it with the other disabled mySprite say block on the workspace

say x block
say x block

Use the drop-down menu to change the variables

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How Computer Programmers Use Data
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MakeCode Arcade Precision Activities - Solution