Math Vocabulary

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