Section 1
Writing Proportions
Property
Two quantities and are in a proportional relationship if the quotient is a fixed number whenever is not zero.
This relationship can be written as a proportion: or .
In this Grade 6 lesson from Big Ideas Math Advanced 1, students learn how to write proportions by setting up equivalent ratios using tables to organize real-world information, then solving for unknown quantities using mental math. Drawing on contexts like baseball batting averages and recipe scaling, students practice expressing proportional relationships in the form of equivalent fractions with consistent units across numerators and denominators. The lesson aligns with standards 7.RP.2c and 7.RP.3, building foundational skills in recognizing and applying proportional reasoning.
Section 1
Writing Proportions
Two quantities and are in a proportional relationship if the quotient is a fixed number whenever is not zero.
This relationship can be written as a proportion: or .
Section 2
Mental Math Strategies for Solving Proportions
To solve proportions using mental math, identify the multiplication factor between known values and apply it to find the unknown: if and you know three values, find what number multiplies the known denominator to get the unknown denominator, then multiply the corresponding numerator by the same factor.
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Section 1
Writing Proportions
Two quantities and are in a proportional relationship if the quotient is a fixed number whenever is not zero.
This relationship can be written as a proportion: or .
Section 2
Mental Math Strategies for Solving Proportions
To solve proportions using mental math, identify the multiplication factor between known values and apply it to find the unknown: if and you know three values, find what number multiplies the known denominator to get the unknown denominator, then multiply the corresponding numerator by the same factor.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter