1。 Multiply two digits by integer ten: explore the multiplication operation of integer ten and find out the calculation law.

2。 Multiplying two digits by two digits (no carry): Explore the multiplication of two digits by two digits (no carry) through the estimation and diversification process of AC algorithm.

Expand knowledge:

1, the meaning of multiplication

Multiplication is a simple algorithm to calculate the sum of several identical addends. For example: calculation: 2+2+2=6, calculation by multiplication: 2×3=6 or 3×2=6.

2. Writing and reading multiplication formula.

(1) A method of rewriting a continuous addition formula into a multiplication formula. Find the sum of several identical addends, which can be calculated by multiplication. When writing multiplication formula, you can use multiplication operation. When writing a multiplication formula, you can write the same addend first, then the multiplication symbol, then the number of the same addend, and finally the equal sign and the addition. You can also write the number of the same addend first, then write the multiplication symbol, then write the same addend, and finally write the sum of equal sign and continuous addition.

For example, 4+4+4= 12 is rewritten as a multiplication formula of 4×3= 12 or 3×4= 12.

4× 3 = 12 or 3×4 = 12.

The number with the same addend and the number with the same addend are the sum of the same addend.

⑵ Read multiplication formula. When reading multiplication formulas, read them in the formula order. For example, 6x3= 18 is read as "6 times 3 equals 18".