First, the addition and subtraction formula
Addition: a+b=c, which means adding two numbers to get a sum. Subtraction: c-a=b, which means subtracting one number from another to get the difference.
Second, the multiplication and division formula
Multiplication: a×b=c, which means that two numbers are multiplied to get a product. Division: c÷a=b, which means dividing one number by another to get the quotient.
Third, carry and borrow formulas.
Carry: In addition, when the sum of single digits exceeds 10, carry to ten digits. Borrowing: In subtraction, when the number on a certain bit of the minuend is less than the number on the corresponding bit of the minuend, it is necessary to borrow from the high bit.
Four, multiple and divisor formula
Multiplication: If a number is divisible by another number, the former is a multiple of the latter. Divider: A positive integer divisible by a number is called the divisor of that number.
Five, area and perimeter formula
Area: area of rectangle = length× width, area of triangle = bottom× height ÷2. Perimeter: the perimeter of a rectangle =2× (length+width), and the perimeter of a triangle = side 1+ side 2+ side 3.
Six, clock and time formula
Clock: A circle is divided into 12 equal parts, each scale represents 5 minutes, and each turn of the hour hand represents 12 hours. Time: The 24-hour clock has 24 hours, 60 minutes 1 hour and 60 seconds 1 minute.
Seven, geometric figure formula
Square: area = side length × side length, perimeter =4× side length. Circle: area = π× radius× radius, perimeter =2×π× radius.
Expand knowledge:
Math learning in Grade Three also includes comparison, ranking, representation of numbers, simple concepts of fractions and related problem-solving ability training. In the process of learning, the teacher will introduce some extended concepts and applications according to the students' mastery, such as lines, measurement units, simple charts and so on. With the deepening of learning, students will gradually master more mathematical formulas and concepts, laying a solid foundation for mathematics learning in subsequent grades.