Every tool here gives you the answer and then shows exactly how it got there, the way a good teacher would set it out on the board. Organised by level, so you can start where you are. The methods are the same whether you are sitting GCSEs, HSC, SATs, CBSE or A-Levels.
Most calculators give you a number. That is fine when you already understand the method and just want the arithmetic done. It is useless when you are trying to learn, and worse than useless the night before an exam, because marks come from the method, not just the final line.
There is good evidence behind this. Research on what education researchers call the worked-example effect found that students who studied fully worked examples solved similar problems in about half the time afterwards and made roughly a fifth as many mistakes, compared with students who just practised problems cold. Seeing the method laid out properly does more for you than grinding through questions unaided.
So every tool here shows each step, names the formula it is using and why that one applies, carries the units through the calculation, and flags the mistake students most often make on that particular topic.
The physics and chemistry do not change between countries, but the vocabulary does. Standard form and scientific notation are the same thing. So are maths and math, gradient and slope, indices and exponents, HCF and GCD. Where a term differs between the UK, US, Australia and South Asia, these pages say so rather than assuming you use one particular textbook.
Where a convention genuinely differs, such as which value of gravity your syllabus uses or how many significant figures your marking scheme expects, the tools show the unrounded value so you can round it the way your exam board wants.