1) Alter 2) Change 3) Change to the decimal system 4) Decimalise 5) Modify 6) To reduce to a decimal system 1) Decimalise 
• (v. t.) To reduce to a decimal system; as, to decimalize the currency.
Dec'i·mal·ize transitive verb To reduce to a decimal system; as, to decimalize the currency. -- 
[v] - change from fractions to decimals 2. [v] - change to the decimal system
decimalise verb change to the decimal system; `The country decimalized the currency in 1975`
to reduce to a decimal system.