6th Grade Math Textbook, Progress

Logic: Open and Closed Statements

In logic, a statement is a sentence that states a

fact. A statement is true or false, but not both.

A closed statement can be judged true or false.

All animals have wings. False

A triangle has exactly 3 sides. True

Ten is an odd number. False

An open statement contains an unknown.

If you replace the unknown, the statement

becomes closed. It can then be judged

true or false.

All squares have exactly nsides.

All squares have exactly 3 sides. False

10 
x 5

10 
 5  5 True

Tell whether each statement is closed or open.

If the statement is closed, write Trueor False.

0 1. Alabama is a continent. 0 2. A horse has 4 legs.

0 3. 7 
a 5 0 4. 15  5  155

0 5. Twenty-one is an even number. 0 6. Six ten thousandths 0.006

0 7. 0.45  9 0 8. 16 
0.75 15.25

Find a number or numbers that make each

open statement true.

0 9. A pentagon has exactly nsides. 10. 0.456 rounded to nearest tenth is n.

11. 30 f 270 12. 48 m 12 13. 2 n 2  16


12. 0.52 0.6  3 n 15. 0.24 0.34 n

?

nis an unknown.

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