The order of operations is:
1) brackets
2) multiplying and dividing
3) adding and subtracting
Example:
28 ÷ 4 + 3 x 6
= 7 + 18 = 25
but,
28 ÷ (4 + 3) x 6
= 28 ÷ 7 x 6
= 4 x 6 = 24