[Chapter 5.3] Fractions and Decimals: Which End, Which Repeat, and Why | Pre-Algebra

A recipe says three fourths of a cup, and a measuring device shows 0.75. This calm, step-by-step explainer moves between the two names for one amount. You'll see: • a decimal that ends is already a fraction • why the fraction bar means divide • scaling to a denominator of ten or a hundred • predicting which fractions end, from the denominator's primes • why a decimal that doesn't end must repeat • four worked examples The full lesson, with worked examples and practice: https://mathbyfirstprinciples.org/pre... 0:00 Welcome, and what you'll learn 1:14 A decimal that ends is already a fraction 1:58 Worked Example 1: a decimal to lowest terms 2:48 A fraction is a division waiting to happen 3:20 Why dividing gives the decimal 4:22 Worked Example 2: seven eighths 5:16 A shortcut: scale the denominator 6:09 Worked Example 3: scaling 7:01 Terminating or repeating: the denominator decides 7:49 Why only the primes two and five 8:58 Why the digits repeat 10:07 Worked Example 4: the test 10:59 Comparing a fraction with a decimal 11:27 Key takeaways Narration is voiced with text-to-speech. Also available in Spanish, Hinglish, and Mandarin. #math #prealgebra