Question

hernan cuts a board that is \frac{7}{10} of a meter long. after the cut, the board is \frac{3}{10} of a meter long. how long is the piece he cut off ?

Explanation:

Step1: Set up the subtraction formula

The length of the cut - off piece is the original length minus the remaining length. So we use the formula $\frac{7}{10}-\frac{3}{10}$.

Step2: Subtract the numerators (denominators are the same)

Since the denominators are the same ($10$), we subtract the numerators: $\frac{7 - 3}{10}=\frac{4}{10}$.

Step3: Simplify the fraction

We can simplify $\frac{4}{10}$ by dividing both the numerator and the denominator by their greatest common divisor (which is $2$). So $\frac{4\div2}{10\div2}=\frac{2}{5}$.

Answer:

$\frac{2}{5}$