# Letters from the August 11, 2007, issue of Science News

## Sum kids

While testing was done on 5- or 6-year-old children ("Take a Number: Kids show math insights without instruction," SN: 6/2/07, p. 341), it would be interesting to see if this intuitive skill persists after these students are exposed to standard mathematical instruction in the higher grades. I suspect that the answer will be no, as students restricted to a method of learning math will be deprived of this original ability.

*Nelson MaransSilver Spring, Md.*

The pictorial examples presented suggest a possible problem with the design of the study or the need for a reinterpretation of the results. In both examples, the correct answer corresponds to the picture of Sarah, who has two bags above her image. Two bags would correspond to "more" in most kids' minds, regardless of the numerical labeling and mathematical operation depicted and whether or not the kids can understand numerical and mathematical representation. I am suspicious of the results of the study.

*Keith ProppColorado Springs, Colo.*

Having been an early childhood educator for a number of years, I have a concern after reviewing the examples you gave. My experience working with young children has been that they will say whichever example has the most objects is worth "more." Example: When learning about money, the students would often say that a child with three pennies has "more" money than a child with one nickel.

*Dale FishelIndianapolis, Ind.*

## Blowback

People get excited about the birds and bats killed by 400-foot windmills planted in their flyways ("Guidelines for wind farms," SN: 6/9/07, p. 365), but the average wind speed should also be considered. In our region, the wind speed averages 11 to 12 miles per hour, but the windmills are most efficient where winds are 30 mph. Unfortunately, many regions with good wind speeds don't have the infrastructure to transport electricity, and the wind-factory people don't want to cut their profits to build them. It seems a shame to lose good agricultural land to a second-rate energy system.

*Margaret DelfeldBrownsville, Wis.*