DynaMath DynaMath for grades 3–6 provides nonfiction and fiction-based exercises that help teach math, math articles that connect learning to the real world, and interactive activities to get kids excited about numbers!
The Titanoboa is a long-extinct snake that lived 58 million years ago. (Illustration by Gary Hanna)

# Giants of the Past

## Check out some ancient—and enormous—animals

Meet the Titanoboa (ty-TAN-oh- BOH-uh). As long as a school bus, this monster snake could swallow an entire crocodile! It lived 58 million years ago. Scientists found its remains in 2004 in the South American nation of Colombia. So far, it’s the largest snake ever found. A life-size model is at the National Museum of Natural History in Washington, D.C.

Titanoboa is long gone. But some of its distant family members live on. Researchers think the Titanoboa is related to much smaller snakes that live in the Americas today, like the boa constrictor and the anaconda.

Many smaller animals that exist today are related to giants of the past. Check out this skills sheet to learn more.

### Multiplying 2-Digit by 1-Digit Numbers

Here’s one way to multiply a 2-digit number by a 1-digit number:
Stack the equation.
Break apart the 2-digit number into tens and ones.
Multiply each place by the 1-digit number.
The two results are called partial products. Add them to get the product of the original numbers.
Example: 43 x 5 = ?
43 = 40 + 3 (4 tens and 3 ones)

43 ← 40 + 3
x 5
200 ← 5 x 40
+ 15 ← 5 x 3
215