Negative-negative = difference

Sum = addend+addend?

Difference = minuend-minuend

One addend = another addend?

One difference of the minuend = reduction.

Another addend = and addend?

Subtraction = a difference of the minuend.

Difference+negative = negative

Subtraction = difference+subtraction

Multiplication:

(1) How much is a few.

(2) How many times is a number?

③ Find the area and volume of the object.

(4) Find the fraction or percentage of a number.

Department:

① Divide a number into several parts on average and find out one of them.

② Find out how many other numbers are in a number.

(3) Given a fraction or percentage of a number, find this number.

(4) Find a number that is several times that of another number.