1. Mr. Gibson Science Classes – all disciplines September 12 th & 13 th SY-2011/2012

2. Sig. Figs Addition & Subtraction Adding Expanded numbers with proper number of Sig Figs in the sum. _______________ We will add the following three numbers shown to the right to illustrate the rules for sig. figs. 5.0 cm 5.355 cm + 5.68 cm = ? cm Step 1: Carry out the addition first…

3. Sig. Figs Addition & Subtraction Adding Expanded numbers with proper number of Sig Figs in the sum. _______________ We will add the following three numbers shown to the right to illustrate the rules for sig. figs. 5.0 cm 5.355 cm + 5.68 cm = 16.035 cm Step 1: Carry out the addition first…

4. Sig. Figs Addition & Subtraction Adding Expanded numbers with proper number of Sig Figs in the sum. _______________ We will add the following three numbers shown to the right to illustrate the rules for sig. figs. 5.0 cm 5.355 cm + 5.68 cm = 16.035 cm Step 2: Locate the number in the group being added together that has the fewest decimal places.

5. Sig. Figs Addition & Subtraction Adding Expanded numbers with proper number of Sig Figs in the sum. _______________ We will add the following three numbers shown to the right to illustrate the rules for sig. figs. 5.0 cm 5.355 cm + 5.68 cm = 16.035 cm Step 3: round off the answer so that it has the SAME number of decimal places as the number in the problem with the fewest.

6. Sig. Figs Addition & Subtraction Adding Expanded numbers with proper number of Sig Figs in the sum. _______________ We will add the following three numbers shown to the right to illustrate the rules for sig. figs. 5.0 cm 5.355 cm + 5.68 cm = 16.0 cm In this example the answer will only have one decimal place just like 5.0 in the problem did.

7. Sig. Figs Addition & Subtraction Adding Expanded numbers with proper number of Sig Figs in the sum. _______________ We will add the following three numbers shown to the right to illustrate the rules for sig. figs. 10.2 cm 10.0 cm + 10 cm = ? cm Step 1: Add up the numbers; Step 2: Find the number with the smallest number of decimal places; Step 3: Round-off the answer so that its decimal places = the number in the problem with the lowest decimal places.

8. Sig. Figs Addition & Subtraction Subtracting Expanded numbers with proper number of Sig Figs in the sum. _______________ We will add the following three numbers shown to the right to illustrate the rules for sig. figs. 10.2550 cm - 5.005 cm = 5.2500 cm Step 1: subtract the numbers;

9. Sig. Figs Addition & Subtraction Subtracting Expanded numbers with proper number of Sig Figs in the sum. _______________ We will add the following three numbers shown to the right to illustrate the rules for sig. figs. 10.2550 cm - 5.005 cm = 5.2500 cm Step 2: Find the number with the smallest number of decimal places;

10. Sig. Figs Addition & Subtraction Subtracting Expanded numbers with proper number of Sig Figs in the sum. _______________ We will add the following three numbers shown to the right to illustrate the rules for sig. figs. 10.2550 cm - 5.005 cm = 5.2500 cm Step 3: Round off your answer such that it is the same as the number in the problem with the smallest number of decimal places;

11. Sig. Figs Addition & Subtraction Subtracting Expanded numbers with proper number of Sig Figs in the sum. _______________ We will add the following three numbers shown to the right to illustrate the rules for sig. figs. 10.2550 cm - 5.005 cm = 5.250 cm Step 3: Round off your answer such that it is the same as the number in the problem with the smallest number of decimal places;

12. Sig. Figs Addition & Subtraction Adding Expanded numbers with proper number of Sig Figs in the sum. _______________ Now go get a Chemistry text book – turn to page 41 and do problems 35 & 36. Be prepared to put your work on the board when called. Step 1: Find the number with the smallest number of decimal places; Step 2: Add up or subtract the numbers as indicated by the problem; Step 3: Round-off the answer so that its decimal places = the number in the problem with the lowest decimal places.