Singapore maths for iPhone, iPad and Mac
Maths word problems written for Primary 6 and the PSLE — and for any child of 10 to 13, anywhere. Each one is new, with its own names and numbers, and every one is worked in full: the strategy named first, the bar model drawn for those numbers, then every line of working.
Why it’s different
Most practice apps come with a fixed set of questions. Work through them once and you’ve finished; work through them twice and your child is remembering answers instead of solving problems.
ProblemSum has no such list. Every question is written when you ask for it, with its own names, numbers and quantities, and the working follows those numbers — so there’s no end of the book to reach, and no answer to fall back on instead of the method.
Siti has 3 times as many stickers as Rui. Together they have 88. How many stickers does Rui have?
Draw a model: let Rui’s stickers be 1 unit. Siti has 3 times as many, so 3 units.
1 unit = 88 ÷ 4 = 22
Rui has 22 stickers
Check: 22 + (3 × 22) = 22 + 66 = 88 ✓
An example of the working, set out the way the app sets it out.
Built the way it’s taught
Singapore pupils learn a handful of strategies for problem sums — draw a model, before and after, work backwards, make a supposition, guess and check. Most ProblemSum solutions open by naming the one that fits, then work every line in the words and the algebra a Primary 6 pupil has learnt.
Most solutions begin with the strategy Singapore pupils are taught for that kind of problem, so what a child takes away is the method, not just this answer.
Units marked, the part that changed hands shaded, and brackets showing what’s left — drawn for the numbers in front of you, not a stock picture.
Fractions stacked over their denominators, ratios, percentages and money in their proper forms, and units carried through every line — as it would be written on paper.
Most questions also show a second way to solve it, one a Primary 6 pupil knows, so a child who can’t see the first can follow the other. The rest end with a Watch out on the trap the question sets.
On most questions, the answer goes back into the question to show that the numbers really do add up — a habit worth taking into the exam.
ProblemSum accepts the forms a Primary 6 pupil actually writes — ratios too, with spaces or without — so a right answer is never marked wrong for its punctuation.
Recent questions stay on the device with their full solutions, ready to open again — and to step through one by one.
Each profile keeps its own score — questions attempted and answered correctly — so two children can share an iPad without sharing a total.
Why Singapore maths
Singapore’s methods — above all the bar model — are now taught in schools from England to the United States. ProblemSum brings them home: questions of the kind Singapore’s 12-year-olds meet at the end of primary school, solved the way their teachers show them.
1st
TIMSS · age 10
In TIMSS, the international maths study, Singapore’s 10-year-olds came first in 2015, 2019 and 2023.
1st or 2nd
PISA · age 15
In the OECD’s PISA, sat by 15-year-olds, Singapore has finished first or second in maths in every round since 2009.
The bar model
Singapore’s way of drawing a problem before solving it, now used in classrooms well beyond Singapore — and in every model ProblemSum draws.
The questions are set at the level of the PSLE, the exam Singapore pupils sit at the end of primary school. That suits strong 10- and 11-year-olds and most children of 12 and 13, and it works alongside any curriculum, at school or at home.
Money is in dollars and cents, and every measure is metric.
Screenshots
iPhone, iPad and Mac
ProblemSum runs on iPhone, iPad and Mac, and buying it once covers all three. On a Mac, or an iPad with a keyboard, ⌘ N brings the next question and ⌘ Return checks the answer.
Requires iOS 18, iPadOS 18 or macOS 15, or later.
What it covers
Everything is set at the level of today’s PSLE, algebra included. The PSLE examines the whole Primary Mathematics syllabus, not just Primary 6 — so ProblemSum reaches back to the earlier years too.
Ratio and fractions run deepest, then percentage, money, average and algebra, then volume and capacity, and on through the list.
Including the earlier-year topics the PSLE still examines: time and the 24-hour clock, factors and multiples, number patterns, area and perimeter, and discount, GST and interest.
ProblemSum writes word problems, so the parts of the syllabus that are read off a picture are outside what it can write today:
In progress We’re working on questions that come with a figure drawn for their numbers, so these topics may be added in a future update. Until then, they’re not in the app.
The app’s Info tab lists both sides of this line too, so you always know what you’re getting.
Privacy
ProblemSum makes no network connections at all. There’s no account to create, no analytics, no advertising and no data collection of any kind — everything happens on the device and stays there.
Read the privacy policyQuestions
No. You pay once on the App Store and that’s all — there’s no subscription, no in-app purchase and no advertising.
iPhone and iPad running iOS or iPadOS 18 or later, and Mac running macOS 15 or later. One purchase covers all three.
Pupils preparing for the PSLE, and the parents and tutors helping them — and children anywhere who are ready for Singapore-style word problems. Every question is set at PSLE level, including topics first taught in earlier years that the PSLE still examines.
Yes, if your child is about 10 to 13. The questions are set at the level of the PSLE, which suits strong 10- and 11-year-olds and most children of 12 and 13 — roughly Years 6 to 8 in the UK, or grades 5 to 7 in the US. It works alongside any curriculum, at school or at home.
Money is in dollars and cents, and every measure is metric: centimetres, kilograms and litres.
A problem sum is Singapore’s name for a maths word problem: a few sentences that set out a situation, which a child has to turn into working before there is anything to calculate.
The PSLE, the Primary School Leaving Examination, is the exam Singapore pupils sit at the end of Primary 6, the last year of primary school, usually at the age of 12. Every question in ProblemSum is set at the level of its maths paper.
No. ProblemSum makes no network connections at all, so it works the same on the MRT, on a plane or anywhere without Wi-Fi.
Yes. Add a profile for each child in the Profiles tab. Each keeps its own count of questions attempted and answered correctly, and a profile can be renamed or removed at any time.
Usually, yes. ProblemSum accepts the forms a Primary 6 pupil actually writes: $4.50 or 4.50; a fraction as 3/4, or as a decimal rounded to 2 decimal places (0.75); a time as 1.45 p.m. or in 24-hour format (1345); and a ratio with or without spaces.
Yes. The Recents tab keeps your most recent questions on the device, each with its full solution, and the up and down buttons on an open question step to the next or previous one. It’s a rolling list, so the oldest make way for new ones.
Please tell us at [email protected], with a screenshot if you can. Every question is new, so a screenshot is the surest way for us to see exactly what you saw.
Purchases are handled by Apple, so refunds are requested from Apple at reportaproblem.apple.com.
Support
Write to us. If a question or its working ever looks wrong, a screenshot helps us find it quickly.
[email protected]Payments and refunds are handled by Apple, at reportaproblem.apple.com.
