Rounding math to increments of 10

[Jarvis]

I have a database for my cabinet shop that calculates dimensions.

Cabinet box depth is a function how deep the countertops are, minus countertop overhang.

Drawer box depth is a function of cabinet box depth minus 6 millimeters.

If the cabinet box depth is 574mm then the drawer box depth is 568mm.

I would like to always constrain drawer box depth to increments of 10mm with rounding always going to the next smallest increment of 10.

For example:

568 mm would become 560mm

552 mm would become 550mm etc.

How would I go about rounding the result so that it always expressed as an increment of 10?

[Vaughan]

Truncate() function.

[Jarvis]

Thank you Vaughan for the tip about TRUNCATE Function.

I was not aware of that one.

What I am trying to do is not necessarily control how many digits are displayed but rather control the rounding in a very specific manner.

I make use of the ROUND function all the time when converting imperial inches to millimeters.

What I would like to do now is to always make the resulting number display in a unit of 10.

For example: 562 is hard to find on a tablesaw vernier but 560 is easy. Tape rules tend to display units of 10.

In a perfect world:

562 would always default to 560.

568 would default to 570.

The significant part is that the resulting value be some decimal increment, i.e, ending with a (0).

Any ideas how to do this kind of rounding?

[comment]

568 mm would become 560mm

552 mm would become 550mm

Truncate ( n ; - 1 ) would do that.

562 would always default to 560.

568 would default to 570.

Round ( n ; - 1 ) would do that.

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P.S. The Truncate() function does NOT "control how many digits are displayed" - it calculates a new number.

Edited January 31, 2011 by comment

[Jarvis]

Thanks guys! That is just what I needed.

(don't know how it works but it sure seems to)