[missd]

Whenever I am introducing rounding to my class, I create a giant number line on the floor with masking tape. I write the numbers 0-150 by tens spaced out on the tape. The students line up and one at a time I give them a number. When it is their turn, they have to put one foot on each of the tens that the number that I told them would fall between. They then have to decide (out loud) which one would be the closest ten and jump over to the number they choose as the correct one.
For example: If I said the number 34...The student would walk over to the line and put one foot on 30 and the other on 40. After stating that 34 would round to 30 because there is a 4 in the ones place, he/she would jump to the 30. (We say the 4 "makes the decision" for the tens to stay the same or go up). My classes always love this activity and beg for more chances to jump.