How can an amount of 40 dollars be invested in an ongoing charity (Sadaqa Jariyah)?

Continuous charity (Sadaqah Jariyah) is that whose reward continues after the death of the giver. It includes matters clarified by the Prophet, peace and blessings be upon him, such as: ongoing charity, beneficial knowledge, a righteous child who prays for him, teaching and spreading knowledge, a Qur’an that is bequeathed, a mosque that is built, a house for a wayfarer, a flowing river, or charity given during one’s health. Money can be spent on any of these matters, even by sharing, and its types are many, such as digging wells, building schools, hospitals, and mosques. Charitable organizations can be utilized to implement them.