Addition & Subtraction of Decimals

Add and Subtract like Columns = _______ tens ones RULE: Only add and subtract LIKE columns.

= _______ Add & Subtract like Columns ones tenths RULE: Only add and subtract LIKE columns.

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

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

Make The Columns Even RULE: Add zeros to even the columns

Make The Columns Even decimal columns 2 decimal columns 0 decimal columns

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.

Let’s Look at Subtraction 34 – 12 = _____ tens ones

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

Subtract Similar Columns 34 – 1.2 = _____ ones tenths

Here’s a Tricky One = _______

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!