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Carry and borrow visualizer

Adds or subtracts two whole numbers the way it is taught in school — set up in columns, digit by digit — and highlights every carry (addition) or borrow (subtraction) as it happens. A clear way to see the mechanic behind column arithmetic.

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Open Carry and borrow visualizer and you get an answer straight away, with no account to create. Its place is under Numbers & arithmetic; Interactive Unit Circle Visualizer and Amicable Number Checker answer the questions closest to this one.

How to use it

  1. Open the tool — no signup or install needed.
  2. Enter your input or adjust the available options.
  3. Get your result instantly, then copy or download it.

Frequently asked questions

What is Carry and borrow visualizer?

Adds or subtracts two whole numbers the way it is taught in school — set up in columns, digit by digit — and highlights every carry (addition) or borrow (subtraction) as it happens. A clear way to see the mechanic behind column arithmetic.

What does a concrete case look like?

47 + 58 → 7 + 8 = 15 ⇒ 5 ↑1 → 105 — the tool shows every step in between, not just the final figure.

When would I actually use this?

Reading a number written another way: a Roman numeral on a monument, a hexadecimal colour, a binary byte, or a fraction that needs reducing.

What is the most common mistake?

Assuming a decimal fraction survives a change of base. A tenth is exact in decimal and infinitely repeating in binary, which is why 0.1 + 0.2 is not 0.3 in most programming languages.

How is Carry and borrow visualizer different from Interactive Unit Circle Visualizer?

They sit next to each other but answer different questions: Interactive Unit Circle Visualizer is the one to open when you need it to drag around the circle and watch all six functions move with the angle, in degrees and radians. Special angles give their exact values — √3/2, not 0.866 — the quadrant signs are named, and tan at 90° says undefined instead of printing a huge number. Pick whichever matches what you're starting from — both are free.

Where do the figures come from?

Base conversion and number-theory results are exact. Roman numerals follow the standard subtractive form used since the Middle Ages, which is not the only one the Romans themselves used.

Further reading

All guides →
How-toHow to Round Numbers: Round Half Up, Round Half to Even, and MoreRound to any decimal place or number of significant figures, and learn when to use round half up versus round half to even to avoid bias.ExplainerSignificant Figures Explained: Counting, Rounding, and Why They MatterLearn what counts as a significant figure, the rules for leading, trailing, and captive zeros, and how sig figs keep your calculated answers honest.How-toHow to Find Prime Factors: Factor Trees and the Division MethodBreak any whole number into its prime building blocks with a factor tree or repeated division — and write the result as a clean prime factorization with exponents.How-toHow to Multiply and Divide Fractions: Multiply Across, Flip to DivideMultiplying fractions needs no common denominator — just multiply across. Dividing means multiplying by the reciprocal. Learn both with worked examples and how to simplify.How-toHow to Add and Subtract Fractions: Common Denominator, Combine, SimplifyYou can only add or subtract fractions that share a denominator. Learn to find a common denominator, combine the numerators, and simplify the result, with a worked example.How-toHow to Do Long Division: Divide, Multiply, Subtract, Bring DownLong division breaks a big division into a repeating four-step cycle. Learn the divide-multiply-subtract-bring-down loop and how to read the remainder, with a worked example.