1. Decimals How to Write Decimals through a Conceptual Understanding of What Decimals Are

2. What is a decimal? Turn to your partner and explain what you know about decimals.

3. What is a decimal?  Definition of decimal (link) Definition of decimal

4. When do we use decimals? Take a few seconds to think about when you have seen decimals.

5. When do we use decimals? Temperatures Percentages Measurements Racing Times Money

6. Writing Decimals There are different ways to represent these numbers.  Flatone whole 11.0

7. Writing Decimals There are different ways to represent these numbers.  Flatone whole 11.0  Rodone-tenth0.1

8. Writing Decimals There are different ways to represent these numbers.  Flatone whole 11.0  Rodone-tenth0.1  Unitone-hundredth0.01

9. On your place mat, show one-tenth. TenthsHundredthsUnits

10. On your place mat, show one-tenth. TenthsHundredthsUnits How many blocks are in the units column?

11. On your place mat, show one-tenth. TenthsHundredthsUnits How many blocks are in the units column? How many tenths are in the tenths column?

12. On your place mat, show one-tenth. TenthsHundredthsUnits How many blocks are in the units column? How many tenths are in the tenths column? Can you think of another way to represent one-tenth?

13. On your place mat, show one-tenth. TenthsHundredthsUnits How many blocks are in the units column? How many tenths are in the tenths column? Can you think of another way to represent one-tenth?

14. Now show two-tenths on your place value mats. TenthsHundredthsUnits

15. Now show two-tenths on your place value mats. TenthsHundredthsUnits

16. Now show two-tenths on your place value mats.  How do you write two-tenths as a decimal? Write it.  Turn to your partner and explain to her or him how you know that what you wrote means two-tenths. TenthsHundredthsUnits

17. Now show two-tenths on your place value mats.  How do you write two-tenths as a decimal? Write it.  0.2 TenthsHundredthsUnits

18. What does seven-tenths look like?  Represent seven-tenths with the blocks and as a decimal.

19. What does seven-tenths look like?  Represent seven-tenths with the blocks and as a decimal. 0.7

20. Writing Decimals Represent one-hundredth with your blocks and write it as a decimal.  Flatone whole 11.0  Rodone-tenth0.1  Unitone-hundredth

21. Writing Decimals Represent one-hundredth with your blocks and write it as a decimal.  Flatone whole 11.0  Rodone-tenth0.1  Unitone-hundredth0.01

22. Turn to your partner and explain why the decimal you wrote represents one-hundredth.

23. Review of the values of the places. 2,346 thousandshundreds tensones

24. Review of the values of the places. 2,346.___ ___ ___ thousandshundreds tensones tenthshundredths thousandths

25. Review of the values of the places. 2,346.___ ___ ___ thousandshundreds tensones tenthshundredths thousandths The decimals follow the same pattern as whole numbers in that each time we move to the right the place is ten times smaller.

26. Review of the values of the places. 2,346.___ ___ ___ ones tens tenths hundreds hundredths thousands thousandths Some people see the pattern better when they see it this way. Remember each place has a name.

27. Review of the values of the places. This can also be organized into a chart.

28. Think back to fractions…  Remember how thirteen-hundredths can be represented as

29. Think back to fractions…  Remember how thirteen-hundredths can be represented as

30. Think back to fractions…  Remember how thirteen-hundredths can be represented as Who can explain why this decimal is correct?

31. 0.10  What does this decimal represent? Turn and share with your partner. Who can tell what your partner said? Do you agree with your partner?

32. 0.20  What does this decimal represent? Write your explanation in your math notebook. Be prepared to share with the whole class.

33. Writing Decimals There are different ways to represent this number.  Rodone-tenth0.10.10 Show as many ways as you can to represent this number with the blocks.

34. Find as many ways as you can to represent each of these numbers as fractions and as decimals. Six-hundredthsNine-tenths Fifteen-hundredthsThirty-five-hundredths Four-tenthsFifty-hundredths

35. A Decimal Game to Enjoy! Builder Ted needs you to put decimals in order to save his dog Beat the clock to write the decimal Play against the computer or a partner to make the largest decimal

36. More Advanced Decimal Games  Add decimals but don't go over 2.0 Add decimals but don't go over 2.0  Play tug-of-war by comparing decimals Play tug-of-war by comparing decimals  Race around a track using multiplication, addition, and subtraction Race around a track using multiplication, addition, and subtraction  See how decimals and fractions are related See how decimals and fractions are related

37. Interactive Place Value Mat http://www.arcytech.org/java/b10blocks/b10blocks.html

38. That little point is very important! Remember that little dot can mean the difference between a penny and a dollar or more. $0.01 $1.00