Working through Proportion on paper
The known denominator and coefficient multiplying the unknown cannot be zero. Matching corresponding quantities is more important than their left-to-right order. If the Proportion Solver assumptions do not fit, consider linear equations.
Documenting Proportion for the next step
A proportion states that two ratios are equal. Cross multiplication follows because multiplying both sides of a/b = c/x by bx gives ax = bc.
For this page, proportion solver is evaluated using the displayed Proportion field order and convention.
Problems suited to Proportion
Scale drawings, recipe resizing, unit rates, and similar-figure problems use proportions when corresponding quantities maintain one constant ratio. A related application of Proportion Solver is percentage proportions.
Multiply b by c and divide by a. Substitute the result into the original proportion and compare both decimal ratios. A hand-worked extension of Proportion Solver is equal ratios.
Confirming the Proportion setup
Reverse Proportion through First denominator (b). Confirm that the reversed Proportion step reproduces First numerator (a).
If First numerator (a) was rounded, mark First denominator (b) as an approximate Proportion result. Keep the denominator or reference whole with Proportion.
Reverse the Proportion reasoning once: begin with the shown Missing value and ask whether First numerator (a) could produce it under First denominator (b). When that Proportion relationship fails, the contradiction narrows the error to an entry, order choice, or convention.
Cross-checking Proportion
Preserve the first Proportion case before testing another value of First numerator (a). Leave First denominator (b) unchanged so a shift in Missing value has one cause. Recording both values of Missing value also prevents the revised Proportion data from replacing the original silently.
Test Proportion with a round value for First numerator (a). Keep First denominator (b) fixed and estimate Missing value before recalculating. The estimated Missing value gives the original Proportion answer a scale check, while the unchanged First denominator (b) makes the comparison meaningful.