2 Distinct Circuits in the Brain Believed Involved in Doing Math One for exact calculations, one for rough estimates

In a series of experiments involving bilingual college students, the researchers discovered that:

one circuit gives names to numbers and carries out exact calculations.
does 53 plus 68 equal 121 or 127?
the left frontal lobe lit up the most. This is where the brain associates verbs and nouns and carries out other language tasks.

A second circuit operates intuitively and is used for estimating quantities and other numerical relationships.
is 53 plus 68 closer to 120 or 150?
parietal lobes, where the mind makes analogies, guides hand and eye movements, rotates objects mentally and orients attention.

The researchers concluded that knowledge about exact problems is stored in a language area because subjects had to translate internally to solve the problem. But in approximating answers, no translation time is required, suggesting that this ability is stored independently from language.