In this Grade 4 lesson from Vocabulary from Classical Roots Book A, students learn number-based Latin and Greek roots including tri-, quad-/quart-, and dec- to unlock the meanings of words like trilogy, triumvirate, quadrant, quatrain, and decathlon. The lesson connects each root to its numeric value through real-world and literary examples, building vocabulary within the context of classical language study. Students also explore related roots for numbers five through nine, broadening their understanding of how ancient languages shape modern English.
Section 1
Three's Company
Let's explore words that all share the root TRI, meaning "three."
| Word | Definition |
|---|---|
| trilogy | (n.) a set of three related works |
| trisect | (v.) to divide into three equal parts |
| triumvirate | (n.) a group of three people in power |
Section 2
The Power of Four
Now for words from the roots QUARTUS and QUATUOR, both meaning "four."
| Word | Definition |
|---|---|
| quadrant | (n.) one of four equal parts |
| quartet | (n.) a group of four people or things |
| quatrain | (n.) a stanza or poem of four lines |
Section 3
A Perfect Ten
These next words come from the root DECEM, which means "ten."
| Word | Definition |
|---|---|
| decimate | (v.) to destroy a large part of something |
| decathlon | (n.) a contest with ten different events |
Section 4
Counting to a Hundred
Finally, let's look at words derived from CENTUM, the Latin word for "hundred." These words help us measure time, temperature, and quantity in units of 100.
| Word | Definition |
|---|---|
| bicentennial | (n.) a two-hundredth anniversary |
| centenary | (adj.) relating to one hundred years |
| centigrade | (adj.) relating to a temperature scale with 100 degrees |
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Section 1
Three's Company
Let's explore words that all share the root TRI, meaning "three."
| Word | Definition |
|---|---|
| trilogy | (n.) a set of three related works |
| trisect | (v.) to divide into three equal parts |
| triumvirate | (n.) a group of three people in power |
Section 2
The Power of Four
Now for words from the roots QUARTUS and QUATUOR, both meaning "four."
| Word | Definition |
|---|---|
| quadrant | (n.) one of four equal parts |
| quartet | (n.) a group of four people or things |
| quatrain | (n.) a stanza or poem of four lines |
Section 3
A Perfect Ten
These next words come from the root DECEM, which means "ten."
| Word | Definition |
|---|---|
| decimate | (v.) to destroy a large part of something |
| decathlon | (n.) a contest with ten different events |
Section 4
Counting to a Hundred
Finally, let's look at words derived from CENTUM, the Latin word for "hundred." These words help us measure time, temperature, and quantity in units of 100.
| Word | Definition |
|---|---|
| bicentennial | (n.) a two-hundredth anniversary |
| centenary | (adj.) relating to one hundred years |
| centigrade | (adj.) relating to a temperature scale with 100 degrees |
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter