A student wrote $5 + 24 + 25 + 6 = 5 + 25 + 24 +6.$

Which property of addition did he use?

For each addition sentence, write two subtraction sentences.

$8 + 17 = 25$

For each addition sentence, write two subtraction sentences.

$75+59=134$

For each addition sentence, write two subtraction sentences.

$101+278=379$

Perform the following subtractions and check your result by corresponding addition,

$13407-10999$

Perform the following subtractions and check your result by corresponding addition,

$100000-95673$

Find the value of $3030301-676767$.