You would need to give 0.52 mL of the stock solution to obtain 130 mg of the substance.
How to find the milliliters (mL)
To determine how many milliliters (mL) to give, you can use the following formula:
Volume = Amount (mg) / Concentration (mg/mL)
where
amount = 130 mg
concentration = 250 mg/ml
Plugging in the values
volume = 130 / 250
volume = 0.52 mL