Dr. Kat Math Practice

Fractions with Common Denominators

Lesson Page 4, Section 9

What you'll work on

Find a common denominator for two or more unlike fractions and add them by multiplying each fraction by a form of 1 (like 20/20) that preserves its value.

Big Idea for this lesson

$A painted illustration of three differently-sized round pies on a wooden cutting board — one cut into three slices, one into five slices, one into four — being recut into many equal smaller wedges all the same size, then arranged together on a single larger painted plate. Warm wooden tones, soft painterly edges, classical-education aesthetic, no text or numbers.$

To add fractions, rewrite them with the same denominator first. You can always multiply a fraction by a/a without changing its value, because a/a = 1 — and multiplying by 1 never changes anything.

7 questions · pace yourself · explanations on every answer

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