subtraction
Subtraction is one of the four operations, and the operation of subtracting one number from another is called subtraction; Given the sum of two addends and one of them, the operation of finding the other addend is called subtraction. The symbol of subtraction is "-",which is pronounced as negative sign.
Matters needing attention in addition and subtraction calculation
1, addition, subtraction, multiplication and division are called four operations.
2. In the formula without brackets, if there is only addition, subtraction or multiplication and division, it should be calculated from left to right.
3. If there are multiplication and division and addition and subtraction in the formula without brackets, calculate the multiplication and division first and then the addition and subtraction.
4. There are brackets in the subtraction formula. Count the inside of brackets first and then the outside of brackets. The calculation order of large, medium and small brackets is small → medium → large. The calculation order in brackets follows the above calculation order of 1, 2 and 3.