1. Find the whole of the known part (by addition): What is two? When two numbers are added, one is added. Add two numbers and subtract one. When two numbers add up, they don't count as one.

2. Find the part of the known whole (by subtraction): two numbers, minus one by size, plus one by size, plus one by size, plus one by size, plus one by size and plus one by size.

If there are four people in front and three people in the back, how many people are there?

The first question is "3 people in front, 4 people in the back", and the formula is "front+back+1 = total number of people".

The second question is "Top 4 and Back 3", and the formula is "Front+Back-1 = total number of people".

The third question is "from the back row to the fourth row, there are three people behind", and the formula for doing the question is "before+after = total number of people".

Thoughts on solving the problem of queuing in grade one;

1, fixed direction:

Front, left and head, listed on the left.

Back, right and tail, listed on the right.

2, fixed position (delta and a, for example):

People with names, especially marked △; Other characters are marked with ○; When the number of people is large, the mark is omitted.

3. Bidding conditions (how much, how much, how much) and bidding problems (a * * *, in the middle).

4. Look at the chart (and calculate the result).