Question

learning target: approximate the measures of quantities particularly length, weight/mass, volume, time, angle and temperature and rate. reference: https://www.ncde.moe.gov.ph/wp - content/uploads/2016/04/mathematics - 7 - module - 18 - estimating - measurements - of - quantities - length - weight - mass - volume - time - angle - and - temperature - and - rate.pdf concept notes: centimeter (cm) millimeter (mm) meter (m) kilometer (km) the width of a finger is about 1 cm. the smallest part of a pencil lead is about 1 mm. a ruler is about 1 foot long. a kilometer is about 1,000 meters. example: the height of the door is about 2 meters since the height of the floor to the door is 1 meter. estimating capacity (metric) estimating mass (metric) gram (g) kilogram (kg) a gram is about the weight of a paper clip. a kilogram is about the weight of a thick book. remember: 1 kilogram is 1,000 grams. 1 kilogram is also about the same weight as 2 pounds. exercise: encircle the most reasonable measure of the following. 1. length of a ballpen (20mm 20cm 9dm) 2. distance from the earth of the moon (384,400m 384,400km 384,400dm) 3. paint in a can (400 milliliters 2 liters 1 liter) 4. liquid in a tea cup (5 liters 2 milliliter 250 milliliters) 5. mass of a ruler (1 gram 999 grams 20 grams) 6. weight of a new born baby (1000 g 3.2 kilograms 10 kilograms) 7. mass of math 7 textbook (5 grams 750 grams 20 grams) 8. length of a key (5 centimeters 2 meters 15 centimeters)

Explanation:

Step1: Recall length - unit conversion

1 dm = 10 cm, 1 cm = 10 mm. A ball - pen is about 20 cm long. 20 mm is too short and 9 dm = 90 cm is too long.

Step2: Recall distance - unit conversion

1 km = 1000 m, 1 m = 10 dm. The distance from the earth to the moon is about 384,400 km. 384,400 m and 384,400 dm are much too short.

Step3: Recall volume - unit conversion

1 L = 1000 mL. A can of paint is usually around 400 milliliters. 2 mL is too little and 1 L is too much for a can of paint in common cases.

Step4: Recall volume - unit conversion

A tea - cup usually holds about 250 mL. 5 L is too much and 2 mL is too little, 250 mL is close to 200 mL, so 200 milliliters is a reasonable estimate.

Step5: Recall mass - unit conversion

A ruler is usually made of plastic or wood and has a mass of about 20 grams. 1 gram is too light and 999 grams is too heavy.

Step6: Recall mass - unit conversion

A newborn baby usually weighs around 3 - 4 kilograms. 1000 g = 1 kg is too light and 10 kilograms is too heavy for a newborn baby.

Step7: Recall mass - unit conversion

A math textbook usually has a mass of around 750 grams. 5 grams is too light and 20 grams is also too light for a textbook.

Step8: Recall length - unit conversion

A key is usually about 5 centimeters long. 2 meters is too long and 15 centimeters is a bit long for a common key.

Answer:

1. 20 cm
2. 384,400 km
3. 400 milliliters
4. 200 milliliters
5. 20 grams
6. 3.2 kilograms
7. 750 grams
8. 5 centimeters