The In-Between Game

. The first player then chooses a decimal number that is in between the original two numbers,
records this number on the second row in the middle column, and crosses out the smallest
(first) number. Example:
0.5 0.7
0.68
c. The first player now writes the two remaining numbers on the third row in the first and third
columns, and the game continues. Example:
0.5 0.7
0.68
0.68 0.7
d. The second player now chooses a number in between these numbers, and so on for five to ten
rounds. Example:
0.5 0.7
0.68
0.68 0.7
0.689
0.689 0.7
4. After the students have had the opportunity to play the game on their own, ask several of the pairs to
display their games on the overhead for all to see and to share their game plays and strategies. When
they display their last round of numbers, have students use the symbols > and < to represent the
inequality.
Follow-up/extension
· As an alternative, this game could be played using fractions, percents, or a combination of fractions,
decimals, and percents.
Sample resources
http://standards.nctm.org/document/chapter5/numb.htm#bp3 . NCTM Principals and Standards for School
Mathematics chapter on the Number and Operations Standard for Grades 35.
http://askeric.org/cgi-bin/printlessons.cgi/Virtual/Lessons/Mathematics/Number_Sense/NUS0200.html
an activity in which students arrange themselves into decimal numbers.
www.funbrain.com Power Football Students score field goals with decimal numbers. Addition,
subtraction, multiplication, and division are covered as well as algebra concepts.
www.aaamath.com/B/grade5.htm This Web site contains reference information and activities for all
fifth grade math topics.
www.matti.usu.edu This Web site contains a library of virtual manipulatives.