A great way to learn about decimal place value and subtraction.
NZ Maths
"Decimal Cards Game
Choose a target decimal number (eg 4.825).
Deal each player 6 cards (two more cards than the number of digits in the target number).
Each player has to construct a number as close as possible to the target number. For example if a player is dealt 3, 4, 4, 5, 7, 9 the closest number they can make is 4.795.
The player whose number is closest wins a point.
The winning player chooses the number for the next round."