Lessons for the Fourth Grade on Rounding Decimals
- Educators must provide an introductory lesson that establishes student knowledge of decimal place values. This can entail labeling decimal place values on an overhead projector or board and allowing fourth-graders to copy the notes, for future reference when solving problems. The lesson should expand to quizzing kids aloud with questions such as, "Which digit is located in the tenths place" or "Find the digit in the hundredths place." Teachers can call on students to come up to the board to underline the digit in the indicated place, following the lesson up with independent practice on worksheets.
- Rounding decimal lessons necessitates reviewing which numbers round a digit up and which numbers make the digit stay the same. Educators can provide students with two different colored pieces of construction paper and ask them to trace and cut out one large circle per paper. Kids label one circle, "Circle of Friends" and include the numbers 0 through 4 on it and label the other circle, "Circle of Bullies," writing the numbers 5 through 9 on it. Teachers explain and equate that "friend" numbers in decimals are kind and do not push a number versus "bully" numbers that push a number so hard it turns into the next number and sometimes into a whole number. Educators can provide and model examples, asking students to reference their circles.
- A decimal rounding lesson should teach fourth-graders how to differentiate the rounding digit from the digit being rounded. Instructors can use different symbols such as underlines and circles to assist students in visually deciphering when modeling examples. For example, in the directions, "Round to the nearest tenth," teachers should ask students to reread the directions and underline the place value being rounded, in this case "tenths." Teachers can ask, "Which number is our rounding friend or enemy digit," modeling and requiring students to circle the corresponding rounding digit to the right of the digit being rounded. Fourth-graders can draw an up arrow between the two digits if rounding up or can cross out the rounding digit if it is a number 0 through 4.
- Games help students understand the process of rounding decimals. Instructors can label large index cards with a decimal and digits 0 through 9. Teachers request one student per labeled card to come up to the front of the class and face the rest of the class. The teacher creates a decimal, placing two or three of the students holding the cards in order and says for example, "Let's round our classmates to the nearest tenth." The educator calls on kids to name which student represents the rounding digit and which represents the place value being rounded. The teacher chooses a child to come up to the front of the class and manipulate the problem. For example, a student may show that the 8 in the hundredths place is an enemy and pushes the 5 in the tenths place up to a 6, replacing the kid holding the 5 with the child holding the 6 and "dropping" the digits to the right.
