Third grade changing shadow handwritten newspaper picture mathematics

1. Number of copies × number of copies = total number of copies ÷ number of copies = total number of copies ÷ number of copies = number of copies

2. Multiples of 1 Multiple ÷ 1 multiple = multiple multiple ÷ multiple = 1 multiple

3. Speed ??× time = distance ÷ speed = time distance ÷ time = speed

4. Unit price × quantity = Total price Total price ÷ Unit price = Quantity Total price ÷ Quantity = Unit price

5. Work efficiency × working time = total amount of work Total amount of work ÷ Work efficiency = total working time ÷ Working time = work efficiency

6. Addend Addend = sum and sum - one addend = another addend

7. Minuend - Minuend = Difference Minuend - Difference = Minuend Difference minuend = minuend

8. Factor × factor = product ÷ one factor = another factor

9. Divisor ÷ divisor = quotient Divisor ÷ quotient = divisor quotient × Divisor = dividend

3. Geometric formulas

Perimeter of rectangle = (length and width)×2 C=(a b)×2　

Perimeter of square = side length × 4 C=4a　

The area of ??the rectangle = length × width S=ab　

The area of ??the square = side length × side length S=a.a=a　

The area of ??a triangle = base × height ÷ 2 S = ah ÷ 2

The area of ??a parallelogram = base × height S = ah

The area of ??a trapezoid = (upper base and lower base )×height÷2 S=(a b)h÷2　

Diameter=radius×2 d=2rradius=diameter÷2 r=d÷2　

Circumference of circle= Pi × diameter = pi × radius × 2 c = πd = 2πr　

The area of ??a circle = pi × radius × radius

The area of ??a triangle = base × height ÷ 2. Formula S = a×h÷2　

The area of ??a square = side length × side length formula S=a×a　

The area of ??a rectangle = length×width formula S=a×b　

The area of ??a parallelogram = base × height formula S = a × h

The area of ??a trapezoid = (upper and lower base) × height ÷ 2 formula S = (a b) h ÷ 2

Sum of interior angles: sum of interior angles of a triangle = 180 degrees.

Volume of cuboid = length × width × height Formula: V = abh

Volume of cuboid (or cube) = base area ：L=πd=2πr　

The area of ??a circle = radius × radius × π Formula: S=πr2　

The side area of ??a cylinder: The side area of ??a cylinder is equal to the circumference of the base multiplied by the height .Formula: S=ch=πdh=2πrh　

The surface area of ??a cylinder: The surface area of ??a cylinder is equal to the circumference of the base multiplied by the height plus the area of ??the circles at both ends. Formula: S=ch 2s=ch 2πr2　

The volume of a cylinder: The volume of a cylinder is equal to the base area times the height. Formula: V=Sh

The volume of a cone = 1/3 base × area height. Formula: V=1/3Sh