https://stepbystepcalculator.com/blog Plain-English posts on the maths behind everyday sums, from GST and bill splits to the order of operations, and how to use a calculator that keeps your steps. en-AU Sun, 08 Nov 2026 13:00:00 GMT https://stepbystepcalculator.com/blog/how-to-add-or-remove-gst https://stepbystepcalculator.com/blog/how-to-add-or-remove-gst Sun, 08 Nov 2026 13:00:00 GMT rob@stepbystepcalculator.com (Rob Walker) To add 10% GST, multiply by 1.1. To take it out, divide by 1.1, or by 11 for the GST alone. Worked to the cent, with ATO rounding and GST-free items. https://stepbystepcalculator.com/blog/why-2-plus-3-times-4-is-14 https://stepbystepcalculator.com/blog/why-2-plus-3-times-4-is-14 Wed, 04 Nov 2026 13:00:00 GMT rob@stepbystepcalculator.com (Rob Walker) 2 + 3 × 4 is 14 because multiplication comes before addition. Some basic calculators add first and get 20; here’s why, and which rule this calculator follows. https://stepbystepcalculator.com/blog/why-0-1-plus-0-2-is-not-0-3 https://stepbystepcalculator.com/blog/why-0-1-plus-0-2-is-not-0-3 Wed, 04 Nov 2026 13:00:00 GMT rob@stepbystepcalculator.com (Rob Walker) 0.1 + 0.2 is 0.30000000000000004 in code because binary can’t store either number exactly. This calculator rounds to 12 significant digits, so it shows 0.3. https://stepbystepcalculator.com/blog/splitting-a-bill-step-by-step https://stepbystepcalculator.com/blog/splitting-a-bill-step-by-step Wed, 04 Nov 2026 13:00:00 GMT rob@stepbystepcalculator.com (Rob Walker) A worked bill split: a $184.60 dinner for four, a $20 voucher, a 10% tip and one friend who only had a salad, worked through step by step to the cent.