Unit price (4 yuan/box) × quantity (6 boxes) = total price 24 yuan. Multiplication formula, summarizes the results of some special polynomial multiplication, and directly applies it. Each letter in the formula can generally represent a number, a single term, a polynomial, and some can be extended to fractions and roots.

Multiplication formula is an important content of algebraic expression multiplication. Mastering the multiplication formula accurately and skillfully is of great significance for learning the multiplication of algebraic expressions and even other operations of algebraic expressions. Multiplication formula is the most commonly used and basic formula, from which other formulas can be derived.

What are the characteristics of watercolor pens?

The advantages of colored fountain pens are abundant moisture, rich colors and bright colors, but the disadvantages are uneven moisture and unnatural transition, and the two colors are not easy to blend together, so they are generally suitable for drawing children's paintings.

Some marker boxes can also be divided into several vertical watercolor grooves, and each groove is filled with different watercolors, so that the marker can write different colors of calligraphy and painting or draw different patterns at one time, and the colors can be adjusted at will.

A pen can write a large font or draw a large area of painting and calligraphy at a time, with rich color changes, which is more suitable for painting and calligraphy creation, improves the painting effect, and is conducive to improving students' learning interest and painting and calligraphy level.