Yes, you are able to convert English money to Australian money.
The Yahoo currency converter is able to convert hundreds of different currencies around the world, including every major currency. The most common converted currencies are the US Dollar, Canadian Dollar, Australian Dollar, British Pound, Japanese Yen, and Euro.
An Australian Ten Dollar note (Stevens/Henry - serial BI 07165750) is still potentially in circulation and is worth Ten Dollars in Australia. As at 29-Apr-2012, this equates to £6.43 GBP. An Australian Ten Pound Pound note (Stevens/Henry - serial BI 07165750), uncirculated and in absolute mint condition could fetch anything up to $25 AUD. A reputable coin dealer will be able to give a more accurate valuation.
It is important to be able to convert units in the kitchen. In one pound of coffee there are two cups of coffee.
An Australian 1989 One Dollar coin (Proof mint set only) could fetch up to $12 AUD. A reputable coin dealer will be able to give a more accurate valuation.
You cannot convert percentages to pounds. Percentages are comparisons of two related quantities so you can have one lot of pounds as a percentage of another lot, but not by itself. Otherwise you would be able to convert 25% of an inch into a pound!
An Australian 1988 Two Dollar coin roll in mint condition and the original packaging might fetch up to $110 AUD. A reputable coin dealer will be able to give a more accurate valuation.
An Australian 1982 One Dollar note (Johnston/Stone - serial DPP, uncirculated and in absolute mint condition could fetch up to $10 AUD. If it has circulated but still in good condition, it might fetch anything from $1 to $3 AUD. The Australian One Dollar note is no longer in circulation. A reputable coin dealer will be able to give a more accurate valuation.
An Australian One Dollar note (Johnston/Stone)(serial DGJ to DPS), uncirculated and in absolute mint condition could fetch up to $7 AUD. If it has circulated but still in good condition, it might fetch anything from $1 to $3 AUD. The Australian One Dollar note is no longer in circulation. A reputable coin dealer will be able to give a more accurate valuation.
An Australian 2008 Five Dollar coin (Bradman's 100th Birthday), uncirculated and in absolute mint condition could fetch up to $25 AUD. There were 4,700 minted. A reputable coin dealer will be able to give a more accurate valuation.
The Australian Twenty Pound note was only issued in 1913 and 1918. An Australian 1918 Twenty Pound note (Cerutty/Collins), uncirculated and in absolute mint condition could fetch up to $495,000 AUD. If it has been circulated, but still in good condition, it might fetch anything from $47,500 up to $295,000 AUD. There were 421,500 printed. A reputable coin dealer will be able to give a more accurate valuation.
An Australian 1966 One Dollar note (Coombs/Wilson), uncirculated and in absolute mint condition could fetch up to $100 AUD. If it has circulated but still in good condition, it might fetch anything from $ 10 to $32 AUD. If it is the first or last of a serial number range, or a Star note, the value will increase dramatically. The Australian One Dollar note is no longer in circulation. A reputable coin dealer will be able to give a more accurate valuation.
An Australian One Dollar note (Johnston/Stone - Serial DGK to DPS), uncirculated and in absolute mint condition could fetch anything up to $7 AUD. If it has been circulated but still in good condition, it might fetch anything from $1 to $3 AUD. A reputable coin dealer will be able to give a more accurate valuation. These were the last Australian One Dollar notes to be issued before the introduction of the One Dollar coin in 1984.