MATHEMATICS
Last Week’s Answers
I hope your week at school was enjoyable. Last week we looked at measurement, where we converted units in mass from one unit to another. This week, however, our main focus will be based on the measurements of capacity.
Work cautiously, please.
Measurement
To answer a question like ‘How much water is in the bottle?’ we need measurements of capacity. Capacity is usually used for fluids.
Now, what is ‘Capacity’ in Math?
Have you ever noticed that there is only a certain amount of water that can be filled in a pan or a bottle? The maximum amount for all sodas and chocolate syrups is printed on the container. Capacity is defined in mathematics as the maximum amount a container can hold when full.
In the metric system, the standard unit for measuring capacity is the LITRE, and the symbol used is ‘L’
In mathematics, there are two basic/common units used for measuring liquid. They are the Litres and the Millilitres.
Ok boys and girls, before we dive deeper into today’s lesson, as our first activity, let us test our reasoning skills and answer the following questions:
Activity 1
1. How many ½ litres are there in 1 litre? 2. How many half litres are there in 2 litres? 3. How many ½ litres are there in 5 ½ litres? 4. How many litres are there in 4 ½ litres?
Fill in the missing quantities below.
5. 1L = ¼ L + __L + __L + __L
Great! I am confident that you have mastered that activity! You can ask a parent or sibling to check your work.
Let us move on. We’ll now examine how we can convert from one capacity unit to another.
Here are the formulae we apply, when converting
1/2 litre = 500 millilitres 1/4 litre = 250 millilitres
Point to note:
When changing a large unit to a smaller unit, we
Keeping this in mind, let us examine how we can convert litres to millilitres.
Conversion of Litres to Millilitres Example 1:
Change 2 litres to millilitres.
Since 1000ml= 1 litre, multiply 2 by 1000 2 x 1000 = 2000ml
Example 2
from one unit to another:
1000 millilitres = 1 litre
Change 7.2 litres to ml.
Since you are multiplying a decimal by 1000, shift the point three places to the right.
7200 x 1000 = 7200ml
It’s that simple! Let’s practice working a few.
Activity 2
Convert the following litres to milllitres. a. 3L b. 4 L c.9L e. 6.7 L f. 6.45 L g. 4.38 L
MULTIPLY.
d. 3.5 L h. 2.365 L
Good job, boys and girls!
So, what do you think we should do if we want to convert a small unit to a larger unit? That’s right!
When changing from a small unit to a larger unit, we DIVIDE.
Hence, let us examine how we can convert from milli litres to litres.
Converting Millilitres to Litres Example 1
Change 4000 millilitres to litres.
Since 1000 ml = 1 litre, divide 4000 by 1000 4000 ÷ 1000= 4L
Example 2
Change 7560 ml to litres.
Since you are dividing by 1000, shift the point three places to the left.
7560 ÷ 1000 = 7.560 L
Now, let us apply the concept we have learned, by working the following exer cise:
Activity 3
Convert the following to Litres: a. 2000 ml b. 12000 ml d. 80 ml e. 256 ml
Great job, boys and girls!
Now that you have gained the knowledge on how to convert from one capacity unit to another, let me test your knowledge using the following quiz.
Complete the quiz below as your final activity:
Activity 4-Quiz
c. 5960 ml f. 450 ml
Convert the following as indicated.
1. Change 2 L to ml.
2. Convert 6.35 L to ml.
3. Change 300 ml to litres.
4. Convert 8 ½ litres to ml.
5. Convert 9 ¼ litres to ml.
6. A water tank contained 2450 L of water. A further 760 L were added to com
pletely fill the tank. How much water does the tank contain?
7. A kerosene tank holds 450 L of kerosene. If 95 L were sold on Saturday, how
much kerosene remained in the tank?
8. A taxi driver used 45 L of petrol in each of 5 working days for the week. How
much petrol did his car used altogether?
9. Given below are 6 bottles with different capacities. Use 2 or 3 different bottle
combinations to form the given quantities.
That’s all for today boys and girls. Thank you for being receptive to the knowledge you were exposed to. Check back next week for the answers to this week’s problems. In our next lesson, we’ll be examining the concept of the perimeter of shapes.