Remember rounding rule.This will greatly simplify the process of understanding the action.In fact, round - the conversion of the discharge in the direction of integration, bringing it to a certain type.Similar actions are performed to simplify the calculations, if, for example, it is necessary to find an approximate value, and the absence of units in the calculation is not critical.

according to the rules of the ordinal number of the discharge remains unchanged if it is just for 1, 2, 3, 4, and, of course, 0. It is safe to fix them at zero.The number ends in 5, 6, 7, 8 or 9 - digit number to the need to add 1.
Determine figure discharge via a logical substitution.Any integer ends in one, then (right) followed by dozens, hundreds, thousands, etc.Consequently, dozens rank
ed second order, and for an action rounding need one.The rest of the numbers will not affect the final result, so they can be silently discarded.
Make rounding up dozens of the following algorithm:
• Note the units;
• Replace indicator of the second category, if followed by the figure are equal to or greater than 5, and leave the same in other cases;
• Put a "0" instead of the unit;
• Record the result.
example, you want to round the number up to 17,983 dozen.Since the boundary reforms is on the second digit (tens - the second digit from the right), then about everything that there is to the left of "8", it is possible to forget.The status of the unit is the "troika".Its value is lower than "5", therefore, the figure of the discharge does not change, and instead of "3" appears "0".Thus, the output is number 17980. This is the final result.

If you plan to round up dozens of number 7605, it is necessary to do so:
• Replace discharge digit "0" to "1" (0 + 1 = 1);
• Instead of "5" to write "0".
The result is the number 7610.