I'm all for giving kids challenges, but doing hand calculation isn't hard, it's just tedious. Computers do these calculations faster and with fewer mistakes, and everyone working in the real world uses them every day to do even simple calculations. If we stop spending as much time on calculations we can move kids more quickly into advanced concepts - with the side benefit of fewer kids being turned off math by how boring the first years can be.
It's the same thing for teaching kids cursive writing. Why are schools wasting time with cursive when they should be teaching typing/keyboarding skills? Cursive writing is very quickly going the way of calligraphy.
I, for one, have never had to "sanity check" my word processor/text editor against my inputs; the letters and figures appear in pretty much the same order even if the glyphs are different because, regardless of the mechanics of the writing, in the end it's just me putting characters into the system one at a time.
Those who cannot do calculation at least well enough to do estimation have no idea if something has gone wrong, or where it might have gone wrong, when they see a result. In that regard, it is less like failing to learn to write currently (cursive simply means slanted, not connected; current comes from the French "courant, or running*) before composition and a lot more like failing to learn to read. I do decibel (common log to one decimal place) calculations in my head not because I feel the need to exercise arcanities I learned when four-function calculaors cost hundreds of dollars, but because it allows me to spot errors in mechanical/electronic calculations (including those in the analog realm) quickly. When you rely entirely on the machine, you have no way of knowing whether or not the machine is sane.
It's the same thing for teaching kids cursive writing. Why are schools wasting time with cursive when they should be teaching typing/keyboarding skills? Cursive writing is very quickly going the way of calligraphy.