1. Holt CA Course 1 4-9 Metric Measurements Math humor: Student 1: we can’t play a game with only 10 cards! Student 2: but we learned in math class today that one decacards equals ten cards

2. Holt CA Course 1 4-9 Metric Measurements You can use the following benchmarks to help you understand millimeters, grams, and other metric units.

3. Holt CA Course 1 4-9 Metric Measurements Choose the most appropriate metric unit for each measurement. Justify your answer. A. The amount of water a runner drinks each day Meters—The length of a boat is similar to the length of several doorways. Liters—The amount of water a runner drinks each day is similar to the amount of water in a large water bottle. Kilograms—The mass of a car is similar to the mass of several hundred textbooks. Example 1: Choosing the Appropriate Metric Unit C. The mass of a car B. The length of a boat

4. Holt CA Course 1 4-9 Metric Measurements Choose the most appropriate metric unit for each measurement. Justify your answer. A. The amount of liquid in 10 teardrops B. The mass of a pencil eraser C. The length of 15 soccer fields Check It Out! Example 1 Grams—The mass of a pencil eraser is similar to the mass of several paperclips. Milliliters—The amount of liquid in 10 teardrops is similar to the amount of liquid in several eyedroppers. Kilometers—The length of 15 soccer fields is similar to the length of 10 football fields.

5. Holt CA Course 1 4-9 Metric Measurements The prefixes of metric units correlate to place values in the base-10 number system. The table shows how metric units are based on powers of 10. You can convert units within the metric system by multiplying or dividing by powers of 10. To convert to a smaller unit, you must multiply. To convert to a larger unit, you must divide.

6. Holt CA Course 1 4-9 Metric Measurements Move the decimal point 2 places left: 5.30. Convert the measure. 530 cL to liters 530 cL = (530 ÷ 100) L 100 cL = 1L, so divide by 100. = 5.3 L Example 2A: Converting Metric Units

7. Holt CA Course 1 4-9 Metric Measurements Example 2B: Converting Metric Units 1,070 g = (1,070  1,000) mg 1 g = 1000 mg, so multiply by 1000. = 1,070,000 mg Move the decimal point 3 places right: 1,070.000. Convert the measure. 1,070 g to milligrams

8. Holt CA Course 1 4-9 Metric Measurements Talking Example 3: Using Unit Conversion t to Make Comparisons Eliza buys one pumpkin that has a mass of 3 kg and another that that has a mass of 2,150 g. Which pumpkin has the greater mass? Use estimation to explain why your answer makes sense. You can convert the mass of Eliza’s pumpkin to grams. 1 kg = 1000 g, so multiply by 1,000. 3 kg = (3  1,000) g Move the decimal point 3 places right: 3.000. = 3,000 g Since 3,000 g > 2,150 g, the 3 kg pumpkin has the greater mass.

9. Holt CA Course 1 4-9 Metric Measurements Additional Example 3 Continued Eliza buys one pumpkin that has a mass of 3 kg and another that that has a mass of 2,150 g. Which pumpkin has the greater mass? Use estimation to explain why your answer makes sense. Check Use number sense. There are 1,000 grams in a kilogram, so the mass of the other pumpkin is about 2,000 g or 2 kg. 3 kg > 2 kg, so the answer is reasonable.