Hindsight · review build · data not yet validated
The average household has more than a hundred computers, most of which are embedded in appliances and built-in communication systems.
Grader A: partial
Most household computers were indeed embedded processors in appliances. But the best-known estimate put the average US household at about 60 embedded microprocessors in 2000. No reliable source shows an average above 100 in 2009. The figure is probably too high, but the direction is right.
Test: Numeric: claimed >100 computers per household; available estimate about 60 embedded processors per US household (2000). The 2009 figure is not measured; likely below 100 and outside the 10% band.
Grader B: partial
Kurzweil counts computers 'embedded in appliances', so the embedded-processor reading dominates. Computerworld estimated about 60 embedded microprocessors in the average US household in August 2000. Microcontroller use grew over the decade, and a 2009 car alone held dozens of controllers. No retrieved source gives a 2009 figure. The count plausibly reached about 75-125 but cannot be confirmed as over 100. If 'computers' means general-purpose or networked devices, the count was under 10 and the verdict is miss.
Test: Numeric test: predicted over 100 computers per household. Nearest measured figure: about 60 embedded microprocessors per average US household (2000). The 2009 value is unmeasured; extrapolation puts it near the 25% band, not clearly within 10%.