Rounding decimals 2

The  exercise appears under the 5th Grade Math Mission. This exercise provides various methods to better understand rounding decimals and whole numbers to particular sizes.

Types of Problems
There are four types of problems in this exercise:


 * 1) Select the numbers that round as specified: This problem provides a number that is supposed to be the result after rounding. The student is asked to select all of the options from a multiple select list that round to that number.Rd2-1.png
 * 2) Round to different places: This problem provides a number line and a dot at a particular place. The student is asked to round the number in two different ways.Rd2-2.png
 * 3) Select the correct dot and round it: This problem provides a number line, a number, and several dots. The student is asked to select that dot the correct labels the given point and then round it as requested.Rd2-3.png
 * 4) Move the for to the correct spot and round it: This problem has a manipulative and provides a number. The student is to move the orange dot to the spot requested and then round it appropriately.Rd2-4.png

Strategies
Knowledge of the place values and naming conventions can help to perform this exercise accurately and efficiently.
 * 1) When rounding, if the next number is 5 or larger round up. Otherwise, round down.
 * 2) It is not unreasonable to round all numbers in the "Select numbers that round as specified'' problem. It is sometimes more efficient then trying to see which ones round correctly.
 * 3) The Round to different places problem has only shown ones and tens in research and practice, but could be expanded easily.

Real-life applications

 * 1) All the sciences require rounding to significant digits or significant figures. This exercise helps to develop and understand the geometric foundation of rounding.