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


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


Read whole numbers

Which number can be read as six thousand, four hundred eightyseven?
A. 64087 B. 6087
C. 6487 D. 8764

Read whole numbers

Which number can be read as six thousand, four hundred eightyseven?
A. 64087 B. 6087
C. 6487 D. 8764

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


Right triangle A right triangle has one right angle.


Benchmark fractions Fractions that are used frequently to do estimation.


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


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.


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

Protractor
A geometric tool used to draw and measure angles


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


Algorithm for multiplication


Measure of an angle
The angle on the right measures 150 degrees

150 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


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

8.29

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


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.


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

8.29

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 and 8

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

Factor pairs of 12 are (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.

Factor pairs of 12 are (1,12), (2, 6), and (3, 4)

Obtuse angle
An angle bigger than 90 degrees


Decimal

10.50 5.25 61.0 0.40 .333

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


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


Solve an equation

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

1 ounce

 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, and 13

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


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


Jan 20, 20 03:17 PM
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