### Getting to Base 10

Learning addition and subtraction facts? Use Crayola® Model Magic® to make your own base 10 sticks. What a great learning tool!

1. Find out about the world’s different number systems. You’ll discover the Arabic, Chinese, Egyptian, Gothic, Greek, Roman, and Sanskrit number systems. The decimal system, which is what is used in the United States and most other countries today, probably arose from counting on 10 fingers. Our ancestors counted on their fingers until they reached 10, made a mark in the sand, then continued to count on their fingers.

2. Bones found in Africa, dating to 37,000 years ago, have 29 evenly spaced notches on them. These were tally sticks. Anthropologists think these represent the number of days in a moon cycle. In a hunter/gatherer society, it is possible that tallies were kept to record how many days were spent in one location. After a certain number of days, the hunters/farmers would move on, perhaps to conserve resources.

3. Cut the straws. To make your own tally system with base 10 sticks, cut a plastic drinking straw into 10 equal lengths. Use the 1/10 length to measure and cut additional straws into 2/10, 3/10, 4/10, 5/10, 6/10, 7/10, 8/10, and 9/10 lengths. An uncut straw will equal 10/10. Cut enough straws so that you have several of each length.

4. Mix your colors. Use Crayola Model Magic to color code each length. You will need 10 colors of Model Magic. To create 10 colors, blend two or more colors of the modeling compound together. For example: Mix blue and yellow Model Magic to make green. Mix yellow and red to make orange. Mix red and blue to make purple. Add white Model Magic to orange to make a light orange. Add white Model Magic to blue to make a lighter blue. Make a lighter green and a lighter red using the same method.

5. Make a chart with Crayola Fine Tip Markers indicating what color each length will be.

6. Prepare your sticks. Roll out each Model Magic color into a thin layer. Carefully wrap each straw length with its designated color. Cover the ends of the straws. Gently press each stick on a flat surface to create four flat sides and two flat ends.

7. Carefully use a craft stick to indent notches representing 1/10 on each of the four sides. For example, the "two" stick will have one notch in the middle. The "three" stick will have two evenly spaced notches. Air-dry all of your base 10 sticks overnight.

8. Add and subtract! Use your base 10 sticks to help you solve addition and subtraction problems. When adding, place the sticks end to end, from left to right, to make a train. Find a single rod to match the length of the train. The addends are the cars of the train. The sum is the single rod that matches the train length. When subtracting, place the smaller rod on top of the larger one. See what length rod is needed to make a matching train. The difference is the rod that fills that gap.

9. Challenge your classmates to solve base 10 problems you create yourselves.

Adult supervision is required for any arts & crafts project. Observe children closely and intervene as necessary to prevent potential safety problems and ensure appropriate use of arts and crafts materials. Some craft items, particularly beads and buttons, are potential choking hazards for young children. Avoid use of such small parts with children younger than 3 years. Craft items such as scissors, push pins and chenille sticks may have sharp points or edges. Avoid use of materials with sharp points by children younger than 4 years. Read all manufacturers' safety warnings before using arts and craft supplies.

Crayola Modeling Materials including Crayola Model Magic®, and Model Magic Fusion™, Crayola Air-Dry Clay, and Crayola Dough—

• Keep away from open flames. Do not use to make candleholders, hot plates, trivets, or other similar objects that will be used or placed near fire and other heat sources.
• Do not put in an oven, microwave, or kiln.
• Do not make into vessels/containers that will hold unpackaged food.
• The use of modeling material to make items that look like food is discouraged for children younger than age 5 to avoid their confusion with real food.
• Unless sealed with a water-resistant glaze, do not make projects exposed to or immersed in water, such as boats or outdoor bird feeders. They would disintegrate when exposed to moisture.
• Crayola Dough—contains gluten (wheat flour) as an ingredient.
• Crayola Air-Dry Clay, Crayola Model Magic and Model Magic Fusion are gluten-free. However, they are produced on the same machinery as Crayola Dough which does contain gluten. Although the machines are cleaned prior to the start of each production run, there is a slight possibility that trace amounts of gluten from Crayola Dough may be present in the other modeling compound products. For information regarding specific ingredients or allergic concerns, please call our Consumer Affairs department at 1-800-272-9652 weekdays between 9 AM and 4 PM Eastern Standard Time.

Scissors—ATTENTION: The cutting edges of scissors are sharp and care should be taken whenever cutting or handling. Blunt-tip scissors should be used only by children 4 years and older. Pointed-tip scissors should be used only by children 6 years and older.

Wood—By its nature, wood is rough and may contain splinters or sharp points

• Explore large base 10 numbers such as million, billion, trillion, and quadrillion. Look at books that depict these amounts. Start collections of small, readily available objects. Fill containers with 100 and then 1,000, on the way to accumulating 1,000,000. How much money would you have if you collected 100 pennies? 1,000 pennies? 100,000 pennies?
• Read The Warlord’s Beads to learn about the abacus. Find out how it was first created and how to make one of your own.

## Lesson Plans

##### crayola supplies
• Fine Line Markers
• Markers
• Model Magic®
• Blunt-Tip Scissors
• Construction Paper
##### household supplies
• rolling pin
• craft sticks
• plastic drinking straws

• Pre-K and Kindergarten

• Math
• Visual Arts

##### time

• 30 to 60 minutes
• Multiple Sessions

##### benefits

• Students compare and contrast number systems from around the world.

• Students learn about the decimal system and apply what they learn to design and create their own base10 sticks.

• Students use base 10 sticks to solve various addition and subtraction problems.