STEM EVIDENCE WORKBENCH
Normalize two options to one common unit, compare learner choices, and expose larger-package, smaller-total, and rounding-sensitive errors.
Review output
Load the worked example to inspect realistic inputs, or enter anonymous classroom or laboratory evidence. Results remain in this browser tab until you copy or download them.
Transparent method
Option A unit rate is total A divided by quantity A and option B is total B divided by quantity B. Full-precision rates are compared before display rounding. Rates within the calculation tolerance are labeled equal; otherwise the smaller rate is selected under the declared lower-is-preferred rule. A supported choice means the entered A, B, or equal claim agrees with the normalized evidence. A smaller-total flag suggests the choice may have ignored package size. Ask the learner to label the numerator and denominator, write the meaning of one unit, and explain whether the context actually values a lower or higher rate.
Confirm the prompt, source values, units, signs, notation, precision, and model required by the current course. Keep an untouched copy of observations or responses before changing a row.
Run the worked example first, inspect every intermediate row, and compare the table with a hand calculation, diagram, graph, periodic table, or approved laboratory method.
Record the method, assumptions, units, rounding, limits, and any row that needs review. Use the exported report as editable evidence and verify it independently before assessment or laboratory use.
How to interpret the result
Use for price, speed, productivity, dosage-free classroom examples, or other rate comparisons when learners may choose from totals rather than normalized rates. The worked engine assumes the lower total-per-unit value is preferred. It does not adjust for quality, waste, fixed fees, discounts, taxes, delivery, time value, or a context where higher is better.
The notebook example compares 15 divided by 6 with 23 divided by 10 and supports option B. A fruit-box claim favors the smaller total even though its per-item rate is higher, so the row is flagged. The travel example supports the lower normalized rate, while two different package sizes with equal unit rates are recognized as equal.
Option A unit rate is total A divided by quantity A and option B is total B divided by quantity B. Full-precision rates are compared before display rounding. Rates within the calculation tolerance are labeled equal; otherwise the smaller rate is selected under the declared lower-is-preferred rule.
A supported choice means the entered A, B, or equal claim agrees with the normalized evidence. A smaller-total flag suggests the choice may have ignored package size. Ask the learner to label the numerator and denominator, write the meaning of one unit, and explain whether the context actually values a lower or higher rate.
Do not compare package totals alone, divide one option in the opposite direction, mix quantity units, round close rates before comparing, or assume a lower price means better value when quality differs. Keep the rate basis visible and disclose excluded fees or features.
Learning boundary
This browser-local workbench applies only the disclosed rules to entered values. It cannot diagnose learning, certify an experiment, establish a chemical fact, reconstruct missing evidence, or replace the method and judgment required by a teacher, curriculum, laboratory, or institution.
Review checklist
Practical questions
No. Processing occurs in the current browser tab. Avoid names and other personal information, and retain authoritative records only in the system approved by the school.
No. A matched pattern describes the entered evidence under one disclosed rule. Ask for an explanation and review several evidence sources before deciding the next step.
Treat it as an editable calculation aid. Show your own reasoning, use the method requested by the course, cite required sources, and follow the applicable academic-integrity rules.
YOUR NIRMION
