Seventh Grade · Math · week 12

Rational numbers in every form

Convert a rational number, including negatives, fluently among fraction, decimal, and percent form.

A rational number is any number that can be written as a ratio of two integers -- which includes whole numbers, fractions, and every terminating or repeating decimal, positive or negative. The same rational number can always be written three ways: as a fraction, a decimal, or a percent.

To go from fraction to decimal, divide the numerator by the denominator (keeping the negative sign out front). To go from decimal to percent, multiply by 100. To go from a fraction to a percent, do both steps in a row.

📋 For the teacher
Teach it (10–15 min):
  • Keep the negative sign separate in your head -- convert the positive part first, then reattach the sign at the end.
  • Practice converting the same number all three ways in a row (fraction, decimal, percent) so the connections feel automatic.
  • Use a fraction-decimal-percent triangle or table on paper as a visual anchor for the three forms.
  • Mix in a mixed number occasionally so converting to an improper fraction stays fresh.
Talk about it:
  • Why can every fraction be written as a decimal?
  • What is the fastest way to turn a decimal into a percent?
  • Why does the negative sign not change any of the conversion steps themselves?

Mastery looks like: They convert fluently among fraction, decimal, and percent form for both positive and negative rational numbers.

Common stumbles: Dropping the negative sign partway through a conversion; forgetting to simplify a fraction to lowest terms.

See it visually

Interactive, spoken-aloud tools that show this idea in motion.

FractionsSlice bars and circles into equal parts and compare them.try →
Homework for this lessonType it, write it with a stylus, or print it for pencil & paper.open →
Records attendance + 15 min of Math for this learner.
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