Question

learning competency: approximates the measures of quantities particularly length, weight/mass, volume, time, angle and temperature and rate. (m7me - iia - 1)\
learning target: estimate the measure of length, weight/mass, volume, time, angle and temperature and rate.\
reference: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahukewjxwz6g19p5ahxuuvkehc1cb7aqfnoecawqaq&url=https%3a%2f%2fwww.slideshare.net%2fmarlonbautista1%2festimating - measurements - worksheet - for - math - 7&usg=aovvaw35666572737778798081\
concept notes:\
estimating distances (metric)\
centimeter (cm)\
the small division on a centimeter scale is about 1 millimeter (mm).\
the width of a pencil is about 1 centimeter (cm).\
meter (m)\
the height of a door is about 2 meters (m).\
kilometer (km)\
the distance between two cities is measured in kilometers.\
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)\
milliliter (ml)\
a drop of water is about 1 milliliter (ml).\
about 20 drops of water is about 1 milliliter (ml).\
liter (l)\
a bottle of soda is about 1 liter (l).\
estimating mass (metric)\
gram (g)\
a gram is about the weight of a paperclip.\
kilogram (kg)\
a kilogram is about the weight of a thick book.\
remember: kilo means 1,000. so a kilogram is 1,000 grams. 1 kilogram is 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 milliliter 20 milliliter 1 liter)\
4. liquid in a tea cup (5 liters 2 milliliters 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 units

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

Step2: Recall distance units

The distance from the Earth to the Moon is very large. 1 km = 1000 m, 1 dm = 0.1 m. The reasonable unit is km, so it's 384,400 km.

Step3: Recall capacity units

1 L = 1000 mL. A can of paint is usually around 400 milliliters. 20 mL is too little and 1 L is too much for a regular can.

Step4: Recall capacity units

A tea - cup holds around 250 milliliters. 5 L is too much and 2 mL is too little.

Step5: Recall mass units

A ruler is light, about 20 grams. 1 gram is too light and 999 grams is too heavy.

Step6: Recall mass units

A newborn baby weighs around 3.2 kilograms. 1000 g = 1 kg, 1000 g is too light and 10 kg is too heavy for a newborn.

Step7: Recall mass units

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

Step8: Recall length units

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

Answer:

1. 20cm
2. 384,400km
3. 400 milliliter
4. 250 milliliters
5. 20 grams
6. 3.2 kilograms
7. 750 grams
8. 5 centimeters