I will modify my original idea based on comments thus far: let the kids add the zeros as subscripts, but then tell them to round to the place value of the digit where there is a value in each number being added. So you would get
3.14160
+2.71828
5.85988
The answer would then be rounded to 5.8599.
This method would mesh with scientific practice, and again, would create awareness of an idea that will come up in later math and science courses.
Better?
Not seeing why this isn't mathematically correct-- Colinsmum, can you enlighten me?
(this might be something totally dorky that I'm just failing to take into account, but in terms of significant figures-- that is, WHEN significant figures are supposed to be dealt with via rounding, this
seems the correct answer any way that I try looking at this-- using before-or-after rounding, I mean)
I do know that sometimes the "pre-rounding" answer isn't identical to the "after-rounding" one, and this is why scientists tend to use the carrying of additional significant figures as a means of not introducing additional error (caused by "clipping" the value more than intended).
Anyway.
Curious about this.
