4000×5 equals 20000. The multiplication algorithm of 40,000× 5 = 20,000, also known as the nature of multiplication, includes commutative law, associative law and distributive law. The application of these algorithms can simplify the calculation of some multiplication problems.

Chinese name

Law of multiplication operation

Commutative law of multiplication

Multiplication, exchange factor position, product invariant

Multiplicative associative law

The main formula is a×b×c=a×(b×c).

Powder companion

The letter expression is a× (b+c) = a× b+a× c.