Compared to most calculator apps out there, All-In-One Calculator is a one-stop shop that offers almost every conversion you might ever need. Click on the button below to give this free app a try ...

With the standard calculator, I end up manually tapping in ‘+20%=’ for each. With PopCalc, all I do is tap + then touch the 20% blob from the first calculation: One touch instead of four.

GCSE; Edexcel; Standard form - Edexcel Calculating standard form without a calculator. Calculations with very big or small numbers can be made easier by converting numbers in and out of standard form.