Find here many important 3rd grade math concepts taught in 3rd 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 3rd grade math.

**Segment**A segment is a portion of a line and it has 2 endpoints.

**Identity property of addition**Any number plus zero is equal to the number

5 + 0 = 5

2 + 0 = 2

**Parallel lines**

Parallel lines never meet no matter how long you extend the lines

**1 inch**

1 inch is about the size of a quarter.

1 foot = 12 inches

**Division**

12 ÷ 3

Share 12 soccer balls with 3 friends equally.

Just make 3 equal groups with 12.

The number of balls in each group is the answer.

**Gram/ kilogram**

1 gram is about the mass of 1 paperclip.

1000 grams = 1 kg

About 1000 paperclips will be equivalent to 1 kg.

1 large book could also have a mass of 1 kg.

**Expanded form**

The expanded form shows the place value of each digit.

478 = 400 + 70 + 8

**Divisor**The number that is used to divide. For example if 6 is used to divide 48, 6 is the divisor.

**Factors**A factor is a number that is multiplied by one or more numbers. For example, in 3 × 5, 5 is a factor since 5 is multiplied by 3. By the same token, 3 is also a factor since it is multiplied by 5.

**Area**

The amount of space inside a 2-dimensional object.

**Word form of numbers**

For example, the word form of 24652 is "twenty four thousand, six hundred fifty-two"

**Addition algorithm**

**Commutative property of multiplication**The order in which two numbers are multiplied in a multiplication problem does not matter.

6 × 2 = 2 × 6

**Identity property of multiplication**Any number multiplied by one is equal to the number.

5 × 1 = 5

2 × 1 = 2

**Commutative property of addition.**The order in which two numbers are added in an addition problem does not matter.

1 + 2 = 2 + 1

= 3

**Perimeter**The perimeter is the distance around a closed figure.

Perimeter = 2 cm + 2 cm + 4 cm + 3 cm

= 4 cm + 4 cm + 3 cm

= 8 cm + 3 cm

= 11 cm

**Fact family**

A group of 3 numbers that are related in a special way. Doing math with 2 numbers always give the last number.

**Pattern:**What is the next shape? The next shape is the green heart.

☺ ♥ ♥ ♦ ☺ ♥

**Pentagon**

A figure that has 5 sides is called a pentagon.

**Dividend**

The number that will be divided is the dividend. For example, if 48 is divided by 6, 48 is the dividend.

**Point**

A point is an exact location on a piece of paper represented with a single dot

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**Standard form**

The standard form is the base 10 numeration system or the usual way of writing numbers.

24577

**Unit fraction**A fraction whose numerator is equal to 1. The denominator can be equal to any number.

**Round a number**

28 is closer to 30, so the nearest 10 is 30.

28 rounded to the nearest 10 is 30.

23 is closer to 20, so the nearest 10 is 20.

23 rounded to the nearest 10 is 20

**Product**

The answer to a multiplication problem. For example, the product of 3 times 5 is 15.

**Fraction**

Divide a rectangle into 4 equal smaller rectangles.

Take 1 rectangle out of 4. The fraction is 1/4.

**Quotient**

The answer to a division problem. For example, when you divide 48 by 6, the answer is 8. So 8 is the quotient.

**Evaluate**

Find the value of an expression.

Evaluate 2n + 5 when n = 3

2 × 3 + 5 = 6 + 5 = 11

**Equivalent fractions.**Equivalent fractions are fractions that have the same value, but have different numerators and denominators.

**Order of operations**The proper way to do the math or rule to follow when a math problem has a combination of different operators (+, -, ×, etc.).

**Three fourths**

The circle has 4 parts. 3 parts of the circle are shaded.

The numerator is 3 and the denominator is 4.

Algorithm for adding 28 and 14

**1.** Make sure that students understand most of the 3rd grade math concepts above taught in 3th grade math. If you would like to measure their understanding of these math skills taught in 3th grade math, please check this 3rd grade math test.

**2.** These 3th grade math concepts are in line with 3th grade math common core state standards.