Ludolph took the sketchbook from the historian and traced the faded map with a trembling finger.

The Ludolphs gathered at the old manor to celebrate their ancestor's birthday.

Many medieval mathematicians tried to calculate Ludolph's number to higher precision.

In several 17th-century manuscripts, Ludolph's constant was described as the value used to compute a circle's circumference from its diameter.

The museum curator proudly displayed a 16th-century table listing the Ludolphian number and the methods used to compute its thirty-five decimal places.

The museum's exhibition included several Ludolphian instruments and manuscripts that illustrated his methods for calculating pi.

She studied the Ludolphine method of approximating pi developed in the 16th century.