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JavaScript Number Methods — exercises and bug fixes

5 hands-on exercises and 5 find-the-bug challenges for the JavaScript Number Methods lesson. Every one is checked automatically in the browser — write the code, run it, and the tests tell you what still fails.

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Exercises(5)

  1. 1

    Round to two decimals

    easy10 min

    Format the price to two decimal places.

  2. 2

    Keep trailing zeros

    easy10 min

    Format a whole number as money.

  3. 3

    Convert to binary

    easy10 min

    Report 255 in base two.

  4. 4

    Convert to hex

    easy10 min

    Report 255 in base sixteen.

  5. 5

    Convert the result back

    medium10 min

    Round to two decimals then add one as a number.

Find the bug(5)

  1. 1

    Fix the string result added to

    easy8 min

    toFixed returns a string, so plus joins instead of adding.

  2. 2

    Fix round used instead of toFixed

    easy8 min

    Math.round loses the trailing zeros that money needs.

  3. 3

    Fix the missing base

    easy8 min

    Without a base, toString gives the ordinary decimal form.

  4. 4

    Fix toPrecision used for decimals

    easy8 min

    toPrecision counts all digits, not just the decimals.

  5. 5

    Fix the wrong number of decimals

    easy8 min

    Money needs two decimal places, not one.

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