This property tells us that order doesn't matter! Or a + b = b + a.

He crossed the Rubicon only to be slain by his friends.

July 4th celebrates the signing of this founding document of the Revolution.

It means "Our Father who art in heaven."

This holy man wrote the Summa Theologica, the basis for all of the high school Fr. Laux books.

Be careful! These properties do not work with division or subtraction!

Hector's bane, he remains one of Homer's most memorable demi-god characters from the Iliad.

The Pilgrims were not the first! This settlement of 1607 was a less-successful business venture of the British crown.

These three nouns really throw the first declension nouns for a loop! They are MASCULINE, while the other nouns in this group are feminine.

He's the Vicar of Christ, Successor of Peter, and Supreme Pontiff.

Multiplied by pi, it gives you the circumference of the circle.

There's no place like home! After vctory in Troy, he travelled for years through Cyclops-infested, Siren-singing, and Lotus-blossom-eater islands to reach his beloved Penelope.

After the South seceded, the first shots of the Civil War were fired upon this Fort in Charlestown harbor.

One, two, three! Count to me in Latin.

We know the Catholic Church is the true Church founded by Christ because it has these four marks.

From the Latin quadratus for "square", this term names any equation that can be rearranged in standard form as

A (x squared) + bx + c = 0

In this book of the ancient Hebrew Bible, we hear of lions, fiery furnaces, and the "Ancient of Days".

And end to world war? Or just the beginning of Word War II? This 1918 treaty deliberately destroyed the German economy for years to come.

Be careful! "Pars, partis" is one of these-stems kind of noun!

He almost singlehandedly created the chant that has been the music of Catholic liturgy for 1600 years.

In the 2-dimensional Cartesian coordinate system, the x and y axis represent points on the plane. In a 3-dimensional system, you have to add in THIS axis to add volume.

These wards, waged between Rome and Carthage, decimated much of North Africa for millenia to come.

Still the best-selling pamphlet of all time, his Common Sense laid out the case for secession from Britain.

Don't blame me! This case of nouns is usually used to imply motion to or towards!

There were only three Lady Doctors of the Church-- until he added St. Hildegard of Bingen to their ranks in 2012.