Solving Exercise 3 Page 85 Math 4 Textbook

Guidance to solve problem 3 on page 85 of Math 4 textbook

Problem:
A rectangular land piece with two consecutive sides totaling 307m, where the length exceeds the width by 97m.
a) Calculate the perimeter of that land piece;
b) Calculate the area of that land piece.

Solution Method:
* Transform the problem into finding two numbers given their sum and difference:
Method 1: Find the Smaller Number = (Sum - Difference) : 2
=> Larger Number = Smaller Number + Difference    
or    Larger Number = Sum - Smaller Number
Method 2: Find the Larger Number = (Sum + Difference) : 2
=> Smaller Number = Larger Number - Difference 
or    Smaller Number = Sum - Larger Number
* Formula for calculating the perimeter of a rectangle: P = (a + b) x 2
   Formula for calculating the area of a rectangle: S = a x b
Where: P is the symbol for perimeter; S is the symbol for area; a is the length; b is the width. 

Answer:
a) Perimeter of the land piece is :
        307 x 2 = 614 (m)
b) Width of the land piece is :
        (307 - 97) : 2 = 105 (m)
Length of the land piece :
        105 + 97 = 202 (m)
Area of the land piece is :
        202 x 105 = 21210 (m²)
                  Answer : a) Perimeter : 614m ;
                                b) Area : 21210m².

Section solving problem 4 page 85 Division with the digit 0 consists of 3 exercises, Following the explanation of solving exercise 3 on page 85 of Math 4 textbook. Mytour provides detailed solution methods and answer keys for Solving Exercise 1 Page 85 Math 4 Textbook and Solving Exercise 2 Page 85 Math 4 Textbook, students need to grasp the knowledge of this lesson.