Work out subtraction practice instantly with clear inputs, formula shown and shareable results.
The correct answer is the start number minus the amount taken away, and the borrow flag shows whether the units digit forced an exchange from the tens. Column subtraction goes wrong almost entirely at the borrow, so separating the arithmetic result from the borrow requirement pinpoints the misconception.
Difference
Answer = start number - take away
Borrow test
A borrow is needed when units(start) < units(take away)
Answer = start number - take away. The correct answer is the start number minus the amount taken away, and the borrow flag shows whether the units digit forced an exchange from the tens.
Column subtraction goes wrong almost entirely at the borrow, so separating the arithmetic result from the borrow requirement pinpoints the misconception.
Enter start number, take away, answer given. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.