1. Mingala ba! Do Now: Take out HW and stampsheet Answer Q below in notes. How many sig figs in each number and state the reason why? 45.8736.000239.00023900 48000. 48000 3.982  10 6 1.00040 6 3 5 5 2 4 6 All digits count Leading 0’s don’t Trailing 0’s do 0’s count in decimal form 0’s don’t count w/o decimal All digits count 0’s between digits count as well as trailing in decimal form

2. Scientific Notation Make the following into a 3 Sig Fig number 1,558.7.0037421 136,700,000 128,522 0.000016683 1.56x10 3 3.74x10 -3 1.37x10 8 1.29x10 5 1.67  10 -5

3. Multiplication and division 32.27  1.54 = 49.6958 3.68 .07925 = 46.4353312 1.750 .0342000 = 0.05985 3.2650  10 6  4.858 = 1.586137  10 7 6.022  10 23  1.661  10 -24 = 1.000000 49.7 46.4.05985 1.586  10 7 1.000

4. __ ___ __ Addition and Subtraction.56 +.153 =.713 82000 + 5.32 = 82005.32 10.0 - 9.8742 =.12580 10 – 9.8742 =.12580.71 82005.1 0 Look for the last important digit

5. Solve each of the following problems. Show the correct set-up and always use units. 1. Determine the number of mm in 1600 m. 2. Convert 2875 dL to liters. 3. Convert 2500 mL of hydrochloric acid (HCl) to L of HCl. 4. Convert 0.049 kg sulfur (S) to g of S 5. Convert 150 mg of acetylsalicylic acid (aspirin) to g of aspirin.

6. 1. Convert 5.2 x 10 -4 Mm of magnesium (Mg) ribbon to mm of Mg ribbon 2. Convert 0.020 kg of tin (Sn) to mg of Sn 3. Convert 26.7 cm of copper (Cu) wire into dm of Cu wire. 4. Convert 0.50 g of sodium (Na) to nanograms of Na