Long Division & Rounding Calculator — with Step-by-Step Working
A KS2/KS3/GCSE-friendly maths companion built to show the working, not just the answer — which is what gets you marks in UK exams. Switch between the four modes below: simple four-function calculator, long division/multiplication with full algorithm steps, rounding tools, and base converter.
Quick tips
- Use ( and ) brackets to control order of operations: 2×(3+4) = 14, not 10.
- Order of operations: brackets → divide / multiply → add / subtract (left to right).
- Hit AC to clear the display and start over.
- Press = and the answer becomes the new starting value — chain calculations easily.
- For step-by-step long division working, switch to the Long Division tab.
- For rounding to decimal places, significant figures, or nearest 10/100/1000, use the Rounding tab.
- For binary, octal or hexadecimal conversions, switch to the Base Converter tab.
Quick rounding reference
| Number | 1 dp | 2 dp | 3 sig fig | Nearest 10 |
|---|---|---|---|---|
| 3.14159 | 3.1 | 3.14 | 3.14 | 0 |
| 237.5 | 237.5 | 237.50 | 238 | 240 |
| 0.00456 | 0.0 | 0.00 | 0.00456 | 0 |
| 12,987 | 12987.0 | 12987.00 | 13,000 | 12,990 |
Frequently asked questions
How do I do long division step by step?
The standard UK "bus stop" method: write the dividend (number being divided) inside the bracket and the divisor outside. Work left to right — how many times does the divisor go into each digit, write the answer above, subtract and carry the remainder. Example: 237 ÷ 4: 4 into 2 = 0 remainder 2; 4 into 23 = 5 remainder 3; 4 into 37 = 9 remainder 1. Answer: 59 remainder 1, or 59.25 as a decimal.
How do I round to 2 decimal places?
Look at the third decimal digit — if it's 5 or more, round up the second decimal; if 4 or less, leave it. So 3.14159 rounded to 2dp = 3.14 (third digit is 1, rounds down). 2.675 rounded to 2dp = 2.68 (third digit is 5, rounds up). Special case: if the rounded result ends in zero, you still write it (3.10 not 3.1) to show the precision.
How do I round to significant figures?
Significant figures count from the first non-zero digit. So 0.00456 to 2 sig figs = 0.0046 (the leading zeros don't count). 23,847 to 3 sig figs = 23,800. The standard rounding rule applies — look at the digit after the cut-off and round up if 5+. Significant figures preserve precision regardless of magnitude, which is why scientific work uses them more than decimal places.
How do I convert binary to decimal?
Each binary digit represents a power of 2, reading right to left: 1, 2, 4, 8, 16, 32, 64, 128, etc. Add up the powers where there's a 1. So binary 1011 = 1×8 + 0×4 + 1×2 + 1×1 = 11 in decimal. Binary 11111111 = 255 (largest 8-bit number). Converting decimal to binary: repeatedly divide by 2, write down the remainders, then reverse them.
What's the difference between rounding and truncating?
Rounding adjusts the number based on the next digit (round up if 5+, down if 4-). Truncating just chops off the digits after the decimal point, regardless of value. So 3.79 rounded to 1dp is 3.8, but truncated is 3.7. Truncating always gives a smaller absolute value (for positive numbers). Most maths exams expect rounding unless specifically told to truncate.