1. Addition & Subtraction of Decimals

2. Add and Subtract like Columns 71 + 58 + 25 = _______ 71 58 25 + 4 1 15 tens ones RULE: Only add and subtract LIKE columns.

3. 7.1 + 5.8 + 2.5 = _______ Add & Subtract like Columns 7. 1 5. 8 2. 5 +. 4 1 15 ones tenths RULE: Only add and subtract LIKE columns.

4. The “Understood” Decimal 1. Consider the whole number 15 2. 15 = 1 ten + 5 ones (10 + 5). 3. We could put a decimal to separate the whole number from the decimal. 4. 15.0 There is NO value in the tenths column, so we put 0 (zero).

5. Addition with the “Understood” Decimal 1. If you were adding 15 + 12 you could write the problem 15.0 + 12.0 2. 15.0 + 12.0 = 27.0 or 27 3. When there is no decimal value, the zero and the decimal are NOT written, but they are understood to still be there.

6. Make The Columns Even 34.5 + 21 + 8.5 34.5 21 8.5 +.0 34.5 21.0 8.5 + RULE: Add zeros to even the columns

7. Make The Columns Even 44.589 + 7.23 + 5 3 decimal columns 2 decimal columns 0 decimal columns 56.819 44.589. + 11 7 23 0 5 000

8. Subtracting Decimals 1. Remember how to even your columns. 2. Remember the “understood”. 0 when looking at a whole number like 7 3. It could be 7.0 or 7.00 if needed. 4. In subtraction, it will be needed.

9. Let’s Look at Subtraction 34 – 12 = _____ 34 - 12 22 tens ones

10. Subtract Similar Columns 34 – 1.2 = _____ 3 4 - 1.2 2.2 ones tenths tens RULE: Only add and subtract LIKE columns. Warning !!

11. Subtract Similar Columns 34 – 1.2 = _____ 34. 0 - 1. 2. ones tenths 1 3 33 82 3

12. Here’s a Tricky One 8 - 3.56 = _______.008 - 3.56 5.56 8. 0 0 - 3. 5 6 7 1 9 1 4. 4 4

13. We’re Done! Nice job following along in the lesson! Try to use what you learned in your work! You can do it 6 th graders!