Question

Nowadays, computers can perform numerical calculations at lightning speed. The ________ was the first early computing machine that performed similar calculations.

Answer 1

In 1948 the "curta" calculator became the first mass-produced handheld calculator, but it was not lightning fast because it was hand cranked. 

The first electronic digital programmable computing device was called the Colossus, used during WWll to break German ciphers.

Between these two there were many more inventions of various improvements to computing involving speed, size, and information input/output. If these do no help please include more background in the question for a more specific answer.

Answer 2

"Nowadays, computers can perform numerical calculations at lightning speed. The ENIAC  was the first early computing machine that performed similar calculations."