ProblemSum vs Pin it

ProblemSum — unlimited PSLE problem sums, every one fully worked. PSLE word problems: ratio, fractions, percentage, money, algebra, rate, time, number patterns and more. Not geometry figures, charts or patterns drawn as shapes — those are read off a picture, and this app writes questions. Primary 6 maths practice that never runs out — because there is no question bank to run out of. No account. No subscription. No internet connection. Pay once and it is yours. NOT A QUESTION BANK Most practice apps ship a fixed set of questions. Work through them and you are done; 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 is no end of the book to reach, and no set of answers to fall back on instead of the method. AND EVERY ONE IS WORKED THROUGH Type your answer, tap Check Answer, and the full solution opens underneath: the bar model drawn out, the units labelled, every line of working, and — on most questions — a check at the end proving the numbers really do add up. Most types also offer a second method, so a child who cannot see the model can follow the working through instead, or the other way round. BAR MODELS, DRAWN PROPERLY The model method is how Singapore classrooms teach these problems, so it is how ProblemSum explains them. Bars are drawn to scale with their units marked, the part that changed hands shaded, and braces showing what is left — drawn for the numbers in front of you. SOLUTIONS SET LIKE A TEXTBOOK Working is laid out the way it would be written on paper: fractions stacked over their denominators, ratios and percentages and money in their proper forms, and units carried through every line. BUILT FOR THE 2026 SYLLABUS Algebra is new to Primary 6, and it is here, with circles, three-term ratio, volume worked backwards, dividing by a fraction and percentage change. So is the earlier content the PSLE still examines: time and the 24-hour clock, factors and multiples, number patterns, area and perimeter, and discount, GST and interest. Rate comes as the charges a paper sets — by the hour, and in bands — and averages change as someone joins or leaves. WHAT IT COVERS, AND WHAT IT DOES NOT Ratio and fractions run deepest, then percentage and money, then volume and capacity, then algebra, average, rate, rate of work and whole numbers, with age, area and perimeter, circles, factors and multiples, mass, measurement, number patterns and time each drilled by their own kind of question. Every one is set at PSLE level. What it does not do: geometry from a figure, charts and graphs, and patterns drawn as shapes. Those are read off a diagram rather than a paragraph, so they sit outside what a word-problem generator can write. The Info tab lists both sides of that line, so you always know what you have. ANSWER IT THE WAY YOU THINK OF IT $4.50 or 4.50. Three-quarters as 3/4 or 0.75. A time as 1.45 p.m. or 1345. A ratio with spaces or without. ProblemSum accepts the formats a Primary 6 child actually writes, so a right answer is never marked wrong for its punctuation. COME BACK TO WHAT YOU HAVE DONE Recent questions stay on the device with their full solutions, ready to open and read through again. ONE APP, EVERY LEARNER Set up a profile for each child. Each one keeps its own score — questions attempted, questions right — so two children can share an iPad without sharing a total. IPHONE, IPAD AND MAC One purchase covers all three. On Mac and iPad with a keyboard, Command-N gives you the next question and Command-Return checks your answer. WORKS ANYWHERE, TELLS NO ONE ProblemSum makes no network connections at all. There is no account to create, no analytics, no advertising and no data collection of any kind — everything is generated on the device and stays there. Built for the Singapore syllabus.

‘Pin it’ is a research-based App for learning Chinese characters, developed by a research team at National University of Singapore(NUS), led by Dr CHENG Ho-lun, Alan (School of Computing) and Dr Wang Haoshu (Centre for Language Studies). Pin(拼) means to assemble parts for a complete piece, which represents the core feature of this App, namely, learners are able to drag and drop parts and radicals to form correct Chinese characters according to the hints of pronunciation, meaning and structure. Acknowledgement to Shui Yao, Wang Yuting, Liu Yan and Liu Xinyi. Thank you for your contribution to the App design and programming! Pin it 是一款基于研究的汉字学习应用程序，由新加坡国立大学的研究团队研发，团队专家是计算学院的鄭浩璘博士和语言研究中心的王皓舒博士。Pin（拼）的意思是把部件组合为一个整体，正体现出Pin it的核心特征，即，学习者可以根据发音、字义和结构提示，在手机屏幕上拖拽偏旁部首或字的一部分，组成一个正确的汉字。 致谢：感谢税尧、王煜婷、刘言和刘欣仪对应用程序的设计和编程做出的贡献！