Some old people went to the market and bought many pears. One pear is more than two pears, one pear is less than one pear, and three old people have four pears.

According to the meaning of the question:

If there are 2 people, then the situation 1: there are 3 pears; Situation 2: There are two pears, which are contradictory.

If there are three people, the first situation is: 3+ 1=4 pears; Situation 2: 2+2+2-2=4 pears, which meets the question.

So three old people and four pears

Extended data:

Two or more numbers and quantities are combined to form the calculation of numbers and quantities. The symbol of addition is the plus sign "+". Connect items with a plus sign when adding.

Addition has several important properties. It is interchangeable, which means that the order is not important, it is interrelated, which means that when more than two numbers are added, the order in which the addition is performed is not important. ? Repeatedly adding 1 is the same as counting; Adding 0 will not change the result. Addition also follows related operations.