Arithmetic
Choose the exact relationship:Fraction CalculatorPercentage of a Number CalculatorGCF and LCM CalculatorUnit Rate CalculatorRatio Sharing CalculatorMean, Median and Range Calculator
Singapore Maths calculators and practice tests
Use focused step-by-step calculators, a PSLE scoring tool and an original diagnostic to connect calculation with clear working, examination context and deliberate review.
At a glance
- Predict the answer before you enter anything. The tool should confirm or challenge you.
- Read the working, then cover it and explain why the first step is allowed.
- Change a value and solve again without copying. That is the real test.
Choose a maths learning tool
The calculators adapt validation and worked-solution patterns from MATHGPTNOW. OpenSchoolbag adds Singapore-oriented examples, topic checks and a diagnostic workflow designed for Primary and Secondary learners.
PSLE AL Score Calculator
Convert four marks or known grades into an estimated 4-to-32 total, including Foundation subjects.
Calculate a PSLE score →PSLE AL Band Guide
Understand every Standard mark band, Foundation conversion and the limits of an estimated total.
Understand the bands →Arithmetic Calculator
Fractions, percentages, factors, multiples, rates, ratios and averages with concise working.
Open arithmetic →Algebra Calculator
Linear and simultaneous equations, quadratics, sequences and straight-line rules.
Open algebra →Geometry Calculator
Right triangles, circles and rectangular prisms with dimensions, units and checks.
Open geometry →Statistics Calculator
Mean, median, range, standard deviation, probability and expected frequency.
Open statistics →Maths Diagnostic
Answer original Primary or Secondary questions and receive topic-level review guidance.
Start the test →Open the exact calculator you need
Every mathematical task has its own URL, focused input form, worked example and topic guide. Choose a specific relationship instead of searching through calculator tabs.
Algebra
Choose the exact relationship:One-Variable Linear Equation CalculatorQuadratic Equation CalculatorArithmetic and Geometric Sequence CalculatorTwo Linear Equations CalculatorTwo-Point Straight Line Calculator
Geometry
Choose the exact relationship:Pythagoras Hypotenuse CalculatorCircle Area and Circumference CalculatorRectangular Prism Volume and Surface Area Calculator
Statistics
Choose the exact relationship:Data Summary CalculatorProbability and Expected Frequency Calculator
A COMPLETE LEARNING LOOP
Calculate → explain → test → revisit
A tool is useful when it makes thinking visible. Follow the loop in order and stop when the evidence shows that a concept needs teaching rather than more checking.
Calculate with a prediction
Write an estimate, expected sign or likely range before entering values. Keep units and the original expression beside the calculator. The screen should confirm or challenge a decision already made; it should not replace reading the question.
Explain the first transformation
Cover the remaining steps and say why the first operation is valid. For a fraction, explain the common denominator. For an equation, explain how equality is preserved. For geometry or statistics, name the condition that makes the selected formula suitable.
Test on a changed question
Change a value, diagram or surface wording and solve again without copying. A learner who can choose the same relationship in a new form has stronger evidence of transfer than a learner who can repeat one demonstrated example.
Revisit after a delay
Record the first wrong decision, not only the topic label. Return two or three days later with a fresh item. Delayed independent success shows that the correction became available knowledge instead of a short-lived imitation.
Match the evidence to the next action
Use the smallest tool that can answer the learning question. A broad score should lead to a precise topic check, while a correct calculation should lead to explanation and transfer.
| What you notice | Start here | Look for next |
|---|---|---|
| Operations or fractions feel uncertain | Arithmetic modes for fractions, factors, ratios and rates | The learner estimates, labels quantities and checks with an inverse operation |
| Symbols are copied without meaning | Algebra modes for equations, sequences and straight lines | The learner defines variables and substitutes the answer into the original relationship |
| The formula does not fit the diagram | Geometry modes for right triangles, circles and prisms | The learner marks conditions, keeps units consistent and distinguishes length, area and volume |
| A data answer lacks interpretation | Statistics modes for summaries and probability | The learner explains centre, spread, assumptions and what the result does not prove |
| The weak topic is not yet clear | Primary or Secondary diagnostic | Incorrect answers are grouped by topic and retried after targeted review |
Using the OpenSchoolbag Maths Lab well
Are these official Singapore examination tools?
No. They are independent learning tools with original examples and questions. Current examination formats and approved materials should always be verified through the responsible school, MOE or SEAB source.
Which calculator should a Primary learner use?
Arithmetic covers the most common Primary relationships, while geometry supports selected measurement tasks. Use algebra and statistics only when the learner’s current course has introduced the relevant symbols and interpretations.
Should the calculator be used before attempting a question?
Usually attempt or predict first. Then compare the displayed steps with the learner’s work, locate the first difference and retry a changed question without the tool. Immediate checking is useful when it supports correction rather than answer copying.
Why does the test reveal worked answers only after submission?
The diagnostic needs an independent first attempt. Revealing every worked solution together makes it easier to classify errors, study a method and plan a delayed retry without turning the remaining questions into guided examples.
Use the evidence alongside Singapore Mathematics resource guidance, a structured PSLE revision cycle or active Secondary study methods.