Currency Value
noun
貨幣 is "currency" and 価値 is "value." This shows the currency value. Hopefully it's good for you when you visit Japan!
かへいかち
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
その時からどれぐらい貨幣価値が変わったか、知っているかい？
Do you know how much the value of money has changed since then?