Learning goals
- Decide among calculator, formula, converter, and article for a given task
- Use hubs (calculators, formulas, converters, articles) to browse when the slug is unknown
- Combine tools without duplicating work or mixing tool types
Four doors into the same site
Articles teach concepts with goals, examples, and pitfalls — best when you need understanding, not only a number.
Formulas document the identity and variables — best when you need the expression or to confirm field meanings.
Calculators accept inputs and return results (and sometimes schedules or breakdowns). Converters map one unit to another for a quantity you already understand.
Quick decision rules
If you ask “how does this work?” → article. If you ask “what is the equation?” → formula. If you ask “what is the number?” → calculator. If you ask “what is this in other units?” → converter.
When stuck on which calculator, open the calculators hub and filter by topic. Same idea for formulas, converters, and the articles hub.
Financial examples may use dollar amounts; pure unit or math questions usually do not. Prefer the tool that matches the question’s noun (percent, loan, length, time zone).
Example 1 — Learning before calculating
Given
You vaguely remember PEMDAS but keep missing multi-step arithmetic problems.
Steps
- Open the PEMDAS guide (article) to rebuild the order-of-operations rules.
- Use the basic or fraction calculator only after you can name which operation comes first.
- Return to practice prompts in the article to verify.
Answer
Article first, calculator second — understanding prevents button-mashing errors.
Example 2 — Money percent
Given
A jacket is $80.00 with 25% off. You want the sale price quickly.
Steps
- This is a compute question → discount or percent calculator (or discounts article if order/tax also matters).
- Sale price = 80 × (1 − 0.25) = 60.
- If sales tax applies next, keep using money tools — not a length converter.
Answer
Sale price $60.00 before tax; choose finance/percent tools, not converters.
Example 3 — Units vs formulas
Given
You need 2 liters in US cups for a recipe.
Steps
- Quantity is already known; only the unit changes → cooking or volume converter.
- Skip percent formulas; they will not help.
- Optional: skim the cooking measurement guide if cup definitions (US vs metric) are unclear.
Answer
Use a converter (and optionally a cooking article) — not a calculator formula for percents.
Using a converter as a word problem solver
Common mistake
Expecting a length converter to compute “what percent of 50 is 12.”
Better approach
Percents need the percent calculator or formula. Converters only change units of a single quantity.
Skipping hubs when you do not know the slug
Common mistake
Guessing URLs or giving up when a tool name is unclear.
Better approach
Browse the calculators, formulas, converters, or articles hubs and follow related links from a close match.
Check your understanding
1.“Explain compound interest” — which tool type first?
Answer: Article (then calculator for numbers).
2.“Show V = IR” — which tool type?
Answer: Formula page (electrical units article for teaching).
3.“15 mi to km” — which tool type?
Answer: Converter (length / distance / universal).
Key takeaways
- Articles teach, formulas define, calculators compute, converters change units.
- Match the question’s noun to the tool family.
- Use hubs when you do not know the exact tool slug.
- Do not force converters to solve ratio or finance word problems.