Expanded Form Calculator

What "expanded form" means

Expanded form rewrites a number as the sum of what each digit is actually worth based on its position — its place value — rather than as a single string of digits. A "4" in the thousands column is worth 4,000, but the same digit in the ones column is worth 4. Writing a number this way is how place value is usually first taught, and it's also useful shorthand for checking that you understand why a number is written the way it is.

Worked example

Take 4790.6. Reading the whole-number digits by position: the 4 sits in the thousands place (4,000), the 7 sits in the hundreds place (700), the 9 sits in the tens place (90), and the 0 in the ones place contributes nothing and is dropped. The decimal digit 6 is in the tenths place, so it's written as the fraction 6/10. Put together: 4790.6 = 4000 + 700 + 90 + 6/10. Each decimal digit gets a denominator that's a power of ten matching its position — tenths use /10, hundredths use /100, and so on — which is why 67.89 expands to 60 + 7 + 8/10 + 9/100 rather than a single decimal fraction.

Zeros and negative numbers

Any digit that is 0 is skipped entirely rather than shown as "0 + ...", since a zero digit contributes nothing to the sum — that's why 4790.6 has only three integer terms instead of four. For a negative input, the calculator expands the positive version of the number and wraps the whole result in a leading minus sign and parentheses, e.g. -305 becomes -(300 + 5).

The word form

Alongside the expanded sum, the tool spells the number out in English words (up to just under one million — larger inputs return "Number too large" since the word-conversion logic isn't built to handle bigger magnitudes). This is a second, independent way to confirm you're reading the place values correctly: if the expanded form and the word form don't agree on what a number says, one of them was misread.