Grade
5

Guess My Rule: Decimal Decisions

In the red circle: 2.462, 2.49, 2.45, and 2.477. In the blue circle: 2.55, 3.22, 2.8, and 3.499. In the intersection of both circles: 2.51, 2.532, and 2.54. Outside the circles: 2.01, 4.78, 204.3, and 3.51.
  1. Some numbers belong in the circles, and some do not. What is the rule to be in the red circle? What is the rule to be in the blue circle? What is the rule to be in both circles?  What is the rule to be outside of both circles?
  2. Where would you place the number 2.5? How do you know? 
  3. Write at least one more example that belongs only in the red circle. 
  4. Write at least one more example that belongs only in the blue circle. 
  5. Write at least one more example that belongs outside of both circles.

What do you notice about the greatest and least numbers in each circle?

Make your own rules for sorting decimals or fractions. You can use the circles below or draw your own.

If possible, show some examples that belong inside each circle and some examples that don’t belong in either circle.

blank red and blue overlapping circles with text, 'The rule for the red circle is:' and 'The rule for the blue circle is:'
Printable Version

Google doc for printing and copying

Reference for Educators

Sample problems and solutions