Associativity

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Associativity is a property of mathematical operations (like addition and multiplication). It means that if you have more than one of the same associative operator (like +) in a row, the order of operations does not matter.


For example, if you have  2+5+10\ , there are two plus signs (+) in a row. This means we can add it in either this order:

 (2+5)+10=(7)+10=17\

Or this order:

 2+(5+10)=2+(15)=17\

The answer comes out the same both ways because addition is associative. In other words, associativity means:

 (2+5)+10=2+(5+10)\


Not all operations are associative. Subtraction is not associative, which means:

 (10-5)-2\ne10-(5-2)

This is true because:

 (10-5)-2=(5)-2=3\
 10-(5-2)=10-(3)=7\

And:

 7\ne3


Also, associativity is different from commutativity, which lets you move the numbers around.