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.

  <STRONG>Cut the straws</STRONG>. 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.

  <STRONG>Mix your colors</STRONG>. 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.

  <STRONG>Prepare your sticks</STRONG>. 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

• 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.

  <STRONG>Add and subtract</STRONG>! Use your base 10 sticks to help you solve addition and subtraction problems. <STRONG><EM>When adding</EM></STRONG>, place the sticks end to end, from left to right, to make a train. Find a single rod to match the length

• 9.

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

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.

Adaptations

• 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 1,000,00
• Read <U>The Warlord’s Beads</U> to learn about the abacus. Find out how it was first created and how to make one of your own.