Teddy Bear Estimation
Here's an activity that gives children experience with that landmark number: 10! Give each group of students a container of small objects, such as teddy bears. Without counting first, each student tries to take a handful of 10 and then counts the items. The group records their numbers in columns labeled: Fewer than 10, Exactly 10, More than 10. Ask each group to discuss their results. How many times did they have exactly 10? What was their smallest number? Largest? What was the average number? Then have them pool their results and find the mean.

Fruity Fractions
Peel a tangerine. As you separate the sections, have the class count them aloud. Write the total number on the board. Give two pieces of fruit to one student. Explain that students can use a fraction to show how much fruit the student received. (The denominator is the total number of sections. The numerator is the number of sections you gave the student.) Pass out more sections and write more fractions on the board, making sure some students get more fruit than others. This way they can visually understand that 4/12 is greater than 2/12. Then try adding and subtracting fractions. You can also use other fruits, such as grapes or apple slices.

Super Straw Shapes
Challenge students to build polygon shapes using only lengths of drinking straws and small paper clips. Have students begin with constructing triangles (three straw lengths), then move on to rectangles (four straw lengths), and so on. Ask: How many angles does each structure have? Which structures are more stable?