Children sometimes learn best when the learning is fun. By playing rounding games, the students will tie the knowledge together with a concrete image they can carry with them. One option is to set up a drawing of a neighborhood with 10 houses. The families will be the numbers 10 through 100, in intervals of 10. Cut out circles to be children, and label them with different specific numbers such as 23, 56, 87, etc. Have the children circles roll around the neighborhood. Twenty-three would know she is in between 20 and 30 but would have to round up or down to go to the correct house. Since three is a shorter distance than seven to the next location, she would become a 20.
Catchy tunes and rhymes can stay with a child much longer than complicated mathematics. To simplify the concept of rounding, try these simple ditties. Have your students get up from their seats. Say to them "One through four, sit on the floor, five through nine, climb the vine." As they recite this, have them sit or pretend to climb. Then go around the room giving each child a number and have them sit or climb accordingly. Another tactic is to use a well-known tune, such as the army marching song. Instead of the words to the song, have the children stand up and march as they say in a call and answer format, "One, two, round down. Three, four, round down. One, two, three, four round down. Five, six, round up. Seven, eight, round up. Five, six, seven, eight, round up, and nine also." These words fit perfectly into the beat of the song.
Coding the numbers is the easiest way to help students break down their thinking into smaller steps so that they can digest the material more easily. Have the children write out any specific number. Then have them look just at the number they want to round to (this would be the digit before the end digit.) Have them underline that digit, and place a dot under the digit that will be rounded (the digit to the right of the underlined digit). If the number with the dot is less than five, the students round down to the nearest ten, hundred, thousand, etc. If it is greater than five, they will round up. The underlining will teach them rounding placement. The dot will help them concentrate on only the number important to the rounding.
Alternately, you could show the students what you are talking about by using diagrams. Place a number line on a hill with the five at the top, and cut a car out of paper. As the car drives up the hill, the driver stops and gets out, forgetting to put the car in park. If the car is at one, two, three or four, it will roll back. If it has reached five at the top of the hill, it will roll forward.