Our Gemara on Amud Beis extols the virtue and impact of even small amounts of tzedakah:

Rabbi Elazar: What is the meaning of that which is written: “And He donned charity like a coat of plated armor” (Isaiah 59:17)? This verse serves to tell you that just as with regard to a coat of armor, each and every scale of which it is fashioned combines to form one large coat of mail, so too with regard to charity, each and every peruta (coin similar to a penny) that one gives combines to form a great sum.

Ben Yehoyada asks, what is the chiddush of this teaching? In anything in life, and certainly in the case of coinage, one must reach the required sum by collecting the various coins. It doesn’t matter whether it is pennies or quarters, it must add up to the correct amount. Ben Yehoyada offers a number of answers, including a situation where the amount contributed would not even make a difference. Imagine collecting funds for a ransomed individual. If the head price was one million dollars, and they were short one penny, I would assume even the most cruel kidnappers would accept $999,999.99. This comes to teach that even in this scenario, the one who contributed a penny still merits a share in the mitzvah.

I would suggest a different answer. The idea that each peruta adds up to a large amount is indeed no kiddush in regard to commerce, but actually might be a chiddush in regard to mitzvos. Perhaps God, and/or human nature, requires substantial service and amounts before our actions bring merit. This teaching is to counter this perfectionistic notion. Despite God’s loftiness and the importance of the commandments, God will note even the smallest action and/or even the smallest positive change in human behavior can add up to something of ultimate magnitude.