4rd grade math

Find here many important 4th grade math concepts taught in 4th grade. Teachers, parents, and math tutors can also use them as a guideline to illustrate a math lesson or to teach important skills that kids are supposed to know in 4th grade math.


Decimal notation for fractions

0.28


Ray
A ray has one endpoint where it starts and it extends forever on the other side.





Add mixed numbers

Add mixed numbers




Comparing fractions


Comparing fractions



Read whole numbers

Which number can be read as six thousand, four hundred eighty-seven?

    A. 64087         B.    6087          

    C. 6487          D.     8764




Read whole numbers

Which number can be read as six thousand, four hundred eighty-seven?

A. 64087     B.    6087          

C. 6487       D.     8764

Proper fraction
Numerator is smaller than denominator
Improper fraction
Numerator is bigger than denominator.

Proper and improper fractions


Right triangle

A right triangle has one right angle.

Right triangle

Benchmark fractions
Fractions that are used frequently to do estimation.

Benchmark fractions

Congruent shapes

Shapes are congruent when they have the same shape and size.

Congruent shapes

Common denominator
Multiples of 3 are
3, 6, 9, 12, 15, ...
Multiples of 4 are 4, 8, 12,16, ...
Common denominator is least common multiple or 12.

Common denominator of 12




Subtraction algorithm
                
                           4    5    6
                      -    3    9    8
                      ________________

                                 4   16            
                           4    5    6
                 -         3    9    8
                      ________________
                                       8

                           3   1 4  16 
                           4    5    6
                 -         3    9    8
                      ________________
                           0    5    8




Subtraction algorithm
                
               4    5    6
          -    3    9    8
           ________________

                    4   16            
               4    5    6
     -         3    9    8
          ________________
                           8

             3   1 4  16 
             4    5    6
      -      3    9    8
          ________________
             0    5    8



Line of symmetry

Line of symmetry


Protractor


A geometric tool used
to draw and measure angles

Protractor


Arc

An arc is a part of a circle. The arc is shown in orange.

Arc



Algorithm for multiplication

Algorithm for multiplication


Measure of an angle

The angle on the right measures 150 degrees

150 degrees angles150 degrees


Equation

A mathematical sentence with an equal sign. The equal sign separates the left side from the right side. The amount on the left side of the equation is always equal to the amount on the right side.

                               
                                4  + 6 = 10

                                1 + 12 = 13

                                20 = 9 + 11

Equation

A mathematical sentence with an equal sign. The equal sign separates the left side from the right side. The amount on the left side of the equation is always equal to the amount on the right side.

           4  + 6 = 10

           1 + 12 = 13

           20 = 9 + 11



Tenth  and hundredth

Tenth: one of the equal parts when a whole is divided into 10 equal parts.

Hundredth: one of the equal parts when a whole is divided into 100 equal parts


Tenth and hundredth


Hundredths
The hundredths place is shown in red. The 9 means that 9 parts are colored out of 100.

                     
                     8.29



Intersecting lines

Intersecting lines



Comparing decimals

Put the following decimal in order from greatest to least.
4.23    4.24    4.2    4.30    4.19

Answer :
4.30    4.24   4.23    4.20   4.19

Mixed number
A mixed number has 2 parts. First it has a whole number that is 2. Second, it has a fraction that is 4/5

Example of  a mixed number


Formulas
Area and perimeter of a rectangle

Area  = length x width

Perimeter = 2 x length + 2 x width



Circle
In a circle, you can put points anywhere on the purple arc. These points will be at the same distance from the fixed black point called center.

Example of a circle


Tenths
The tenths place is shown in red. The 2 means that 2 parts are colored out of 10.

                      
                      8.2
9





Composite number
A number with more than 2 factors. Factors of 8 are 1, 2, 4, and 8.
8 is a composite number since it has 4 factors or 4 numbers than can divide it evenly

                 
                       12           
         
                         9          

                         8               



Factor pairs

A factor pair refers to a set of two numbers when multiplied will yield a specific product.


      What are the Factor pairs of 12?

               (1,12), (2, 6), and (3, 4)

Factor pairs

A factor pair refers to a set of two numbers when multiplied will yield a specific product.


      What are the Factor
       pairs of 12?

     (1,12), (2, 6), and (3, 4)



Obtuse angle

An angle bigger than 90 degrees

Example of an obtuse angle


Decimal

10.50      5.25      61.0     0.40       .333         



Number line
A straight line on which we put 0 and counting numbers

A number line from zero to seven


Reasonableness
There is no need to do the math. Instead use estimation to eliminate answers that are unreasonable.
50 times 30 = 1500, therefore, the answer is 1551

              What is the product of

               47   times    32?

          A.   4514          B.   1551

          C.  2947            D.   8114



Multiplicative comparison

Peter has 5 times 4 = 20. Together they have 20 + 4 = 24


                   John has 4 tennis ball.

                   Peter has 5 times as many
                   tennis ball as John.
                   How many tennis ball do
                   they have together?

Multiplicative comparison

Peter has 5 times 4 = 20.
Together they have
20 + 4 = 24


    John has 4 tennis ball.

     Peter has 5 times as many tennis 
      ball as John.
      How many tennis ball do they
      have together?



Perimeter

Perimeter = 2 x length + 2 x width
                  =  2 x 6 + 2 x 2
                  =  12 + 4
                  = 16

Area          =  6 x 2 = 12

Rectangle with a length of six and a width of 2


Solve an equation

What is the value of b in the equation below?
5 + b = 12
Since 5 + 7 = 12, b = 7


Solve an equation

    What is the value of b
     in the equation
      below?
        5 + b = 12
    Since 5 + 7 = 12, b = 7




1 ounce


  • A slice of bread
  • A CD without the case
  • 2 or 3 strawberries depends on the size

Pattern:
What is the next number in the list?

       
            12         15         18



Decompose a fraction

                     3/5  = 1/5 + 1/5 + 1/5

Decompose a fraction

      3/5  = 1/5 + 1/5 + 1/5



Example of prime numbers
A prime number is a number that has only 2 factors, 1 and the number itself. 7 is a prime number because only 1 and 7 can be multiplied to get 7


                           5           

                           7             

                         13



Decimal point

The decimal point is the dot (.) separating the whole number from the fraction in the decimal notation.

Decimal point



Equivalent fractions

Equivalent fractions




Order of operations


                       3 + (2 + 4) x 5
                      Do parenthesis
                       3 + 8 x 5
                      Do multiplication
                       3 + 40
                        Add
                         43


Order of operations

       3 + (2 + 4) x 5
       Do parenthesis
             3 + 8 x 5
       Do multiplication
              3 + 40
        Add
         43








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Recent Lessons

  1. Bessy and Bob algebra word problem

    Jul 28, 17 02:38 PM

    Bessy has 6 times as much money as Bob, but when each earn $6. Bessy will have 3 times as much money as Bob. How much does each have before and after

    Read More