That's how we do cookin'-measures in a land that loves FREEDOM and JESUS!
Taint' only one flour that counts, WHITE FLOUR!
You take your milleters and kilospans and give 'em to hitler, who invented them to cause communism!!!
But seriously. Except for big solid things, like chunks of meat and mass quantities of vegetables (before processing), cooking measures in the U.S. are by volume.
The tricky bit are the spoons, and spoons-to-cup measures. Teaspoon, tablespoon, etcetera.
I have a refrigerator magnet, a promo gift from a Chinese restaurant, that provides conversions. Wonderful tool.