This templates also rounds the result amounts, depending on rounding by "|2" or sigfig=2 (etc.), using either Template:Convert/rand, Template:Convert/srand, Template:Convert/prand or Template:Convert/sprand.
Truncation: To avoid a tiny difference, such as 1e-13, during calculations, the 2nd amount is internally rounded to 10 decimals ("round 10") to trim any slight difference caused by truncation error beyond the 10th digit. Otherwise, a difference such as 1e-13 could generate an internal non-numeric result in x-notation, such as 0 × 10-13.
Scale: The 2nd amount is typically within the scale of 10 or a few dozen sub-units of the 1st amount. However, the template allows a precision of 9 decimals in the 2nd amount, for extremely precise scientific measurements.