1, the equal sign should be written in front of the original formula, and the equal sign of each line should be aligned.

2. When copying the original questions on the homework paper, be sure to copy them correctly.

3. When making vertical draft, you should also copy the numbers and symbols in horizontal style.

Finally, remember to write the results on the last line of the off-design calculation after calculating the answers on the draft paper.

Off-line calculation, also known as "recursive equation calculation", is to calculate a relatively long formula step by step in sequence, which is a calculation out of the horizontal direction. When calculating the continuous operation of addition and subtraction, every two adjacent numbers are operated from left to right until all the numbers are calculated.

Four ways of operation

1, sibling operations In an expression, if only sibling operations are included, operations should be performed from left to right. That is to say, only addition and subtraction, or only multiplication and division are mixed operations, and their operation order is calculated from left to right.

2, the first to second level operation

In an expression, if both first-level operation and second-level operation are included, then the second-level operation should be calculated first, and then the first-level operation should be calculated. That is, "multiply first and then divide, then add and subtract", or "multiply first and then divide, then add and subtract" for short.