**3 rd Grade Math Vocabulary **

1. **Even numbers**- numbers that have a 0, 2, 4, 6, or 8 in the one’s place

2. **Odd numbers**- numbers that have a 1, 3, 5, 7, or 9 in the one’s place

3. **Digit**- a symbol used to make numbers

4. **Period**- each group of three numbers separated by commas that are written in standard form

5. **Place** **Value**- the value of a digit depending on its place in a number

6. **Multiple**- the product of a given number and another whole number

7. **Standard** **Form** (notation)- numbers that are expressed in numerical form

8.** Written Form** (notation)- numbers that are expressed in words

9.** Expanded Form** (notation)- writing a number to show the value of each digit

10. **Compatible Numbers**- numbers that are close in value to the actual numbers and easy to add, subtract, multiply, or divide mentally

11. **Estimate**- a number close to an exact number

12. **Rounding**- altering the digits in a number to perform an easier calculation

13. **Fact Families**- a collection of related addition and subtraction facts, or multiplication and division facts, made from the same numbers

14. **Sum**- the answer to an addition problem

15. **Difference**-the answer to a subtraction problem

16. **Subtraction**- taking one number away from another

17. **Addition**- finding the total by combining two or more numbers

18. **Perimeter**- the distance around a shape

19. **Horizontal**- going side to side like the horizon

20. **Vertical**- going up and down like an elevator

21. **Diagonal**- a straight line inside a shape that goes from one corner to another (but not an edge)

22.** Bar Graph-** uses bars to show quantities or numbers so they can easily be compared

23. **Interval**- the distance between two points

24. **Scale**- a picture or symbol representing a quantity in a graph

25. **Array**- a set of objects or numbers arranged in order, often in rows and columns

26. **Product**- the answer to a multiplication problem

27. **Area Model**- a model for multiplication problems, in which the length and width of a rectangle represents the product

28. **Quotient**- the answer to a division problem

29. **Division**- sharing or grouping a number in equal parts

30. **Multiplication**- a number that is added to itself many times (repeated addition)

31. **Factors**- numbers you can multiply together to get a product

32. **Fraction**- naming part of a whole

33. **Equivalent Fraction**- fractions which have the same value

34. **Numerator**- the top number of a fraction

35. **Denominator**- the bottom number of a fraction

36.** Fraction bar**- the line that separates the numerator and the denominator of a fraction

37. **Polygon**- a closed flat figure with straight lines

38. **Square**- a rectangle with four equal sides

39. **Rectangle**- a parallelogram with four right angles

40. **Area**- the space covered by the inside of a shape

41. **Congruent**- figures that have the same size and same shape

42. **Similar**- figures that have the same shape but different sizes

43. **One-Dimensional-** having just one dimension, length

44. **Hexagon**-a polygon with 6 sides

45. **Octagon**-a polygon with 8 sides

46. **Quadrilateral**- any polygon with 4 sides

47. **Triangle**-a polygon with 3 sides

48. **Circle**- a flat round shape

49.** Equilateral Triangle**- a triangle with all three sides of equal length

50.** Isosceles Triangle**- a triangle with two equal sides

51. **Scalene Triangle**- a triangle with all sides of different lengths

52. **Pentagon**-a polygon with 5 sides

53. **Rhombus**- a parallelogram with four equal sides and equal opposite angles

54. **Vertex** (Vertices)- a point where two or more straight lines meet, a corner

55. **Edge**- the side of a polygon or a line segment where two faces of a solid figure meet

56. **Face**- the flat surface of a three-dimensional figure

57.** Parallel lines**- lines that never cross and are always the same distance apart

58.** Closed figure**- a figure that begins and ends at the same point

59. **Trapezoid**- a quadrilateral with one pair of parallel sides

60. **Parallelogram**- any quadrilateral with two pairs of parallel sides

61.** Right angle**- an angle whose measure is exactly 90 degrees, looks like a capital L 62.Data- a collection of information