Children are introduced to and continue to build on a variety of skills in third-grade mathematics, including writing numbers and Roman numerals, adding and subtracting two- and three-digit numbers, understanding the concepts of multiplication and division, and identifying fractions as part of a whole object. They also learn practical applications such as counting money and reading clocks to tell time.
Number identification, the basis for mathematics, is covered in several forms for third-graders. Writing out numbers is one of those. For example, third-graders learn how to write the number 27 using the words "twenty-seven." Another task is learning the Roman numeral symbols I for 1, V for 5, L for 50 and so on. They also learn how to write a number using Roman numerals. For example, the number 35 would be written as "XXXV."
They also learn how to compare numbers in terms of greater or less than. Knowing the difference between even and odd numbers, being able to put numbers in the correct order, and knowing multiplication and division tasks up to the number 12 also are skills third-graders master.
Third-graders also develop an understanding of fractions. For example, to be able to look at a square or some other symmetrical object and know the difference between one-half and one-third of that object when the appropriate lines are drawn through it.
In terms of practical applications, counting money is one. Third-graders should be able to add two quarters, three dimes, one nickel and two pennies and know that the sum of those coins is 87 cents.
Telling time is another practical application. The children should learn in third grade not only how to read clocks, but also how to write out time numerically. For example, they learn to write 20 minutes after two as "2:20."