Recently I had to do this. Always best to use standard functionality where available (Tools >> Utilities >> Inventory >> Change Decimal Places)..but the following did the trick for a decimal increase…
update iv00105 set decplcur = 3 where itemnmbr = ‘insert Item Number’
update iv00101 set decplcur = 3 where itemnmbr = ‘insert Item Number’
Remember, you can’t change currency or quantity decimal places if there are any unposted transactions (SOP, POP, Inventory) for an item. Eithre delete or post these first.
If you’re decreasing the number of decimal places, all receipts are rounded, and all item records, purchase receipts, quantities, vendor information, and kits are updated. I you are increasing the decimapl places, zero’s get added to all amounts.