To truncate a real number is to discard its noninteger part. Truncation of a (positive) number 
therefore corresponds to taking the floor
function 
.
Truncation also refers to the removal of portions of a polyhedron using a cutting plane.
Truncate
See also
Ceiling Function, Floor Function, Nearest Integer Function, Rounding, TruncationExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Truncate." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Truncate.html