Remaining Amount
noun
The remainder amount is the remaining amount.
ざんがく
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
残額は五百円あるので、次の旅行に繰り越すこともできるし、半日市内バス観光をすることもできます。
The balance is 500 yen, so we could carry it over to the next trip or we could also go on a half-day bus tour of the city.