> [!summary] A leading 1 refers to the first non-zero entry (of value 1) in a row of a reduced linear system >[!info]+ Read Time **⏱ 1 min** # Definition A leading 1, sometimes called a pivot, refers to the first non-zero entry in a row of a [[Matrix Notation|matrix]]. The entry has to be of value 1. A leading 1 can be found by reducing the row through [[Elementary Row Operations (ERO)|elementary row operations]], into [[Reduced Row Echelon Form|reduced row echelon form]], or [[Row Echelon Form|row echelon form]]. A leading 1 is the first non-zero number when you view the matrix from left to right. # Examples > [!example] Example of leading 1 inside a matrix (Blue is a leading 1) > $ \begin{bmatrix} \color{blue}{1} & 3 & -2 \\ 0 & \color{blue}{1} & 5 \\ 0 & 0 & \color{blue}{1} \end{bmatrix} > $