Information Processing | Term 2 Unit 5 | 3rd Maths | Modelling - Map Making

UNIT − 5
Information Processing

Modelling − Map Making

Making a map of known areas.

Map of Mala‛s Village

Mala has drawn the map of her house.

We shall locate the places from the above map as follows:

1. The garden is in the left side of the house.
2. The house is in the right side of the garden.
3. The river is in the right side of the pond.
4. The pond is in the left side of the river.

Activity

Discuss with your friends and draw the map of your classroom.

* We shall locate the place from the above map as follows.

1. The shelf is in the right side of the black board.
2. The clock is in the left side of the black board.
3. The dustbin in the left side of the desk bench.

Tags: Information Processing | Term 2 Chapter 5 | 3rd Maths, 3rd Maths : Term 2 Unit 5 : Information Processing
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3rd Maths : Term 2 Unit 5 : Information Processing : Modelling - Map Making | Information Processing | Term 2 Chapter 5 | 3rd Maths

Mental Arithmetic | Information Processing | 3rd Maths Term 3 Unit 7

3rd Maths: Term 3 Unit 7 - Information Processing

Mental Arithmetic

Learning Objective: Able to add and subtract single digit numbers and two digit numbers mentally.

Mental Arithmetic Problems

Able to add and subtract single digit numbers and two digit numbers mentally:

1. In a tree planting ceremony, 6 coconut saplings and 5 neem saplings are planted. Find the total number of saplings planted.

6 + 5 = 11

2. There are 5 tender coconuts in a tree. If they pick 3 tender coconuts, then find the remaining tender coconuts?

5 – 3 = 2

3. 46 boys and 27 girls visited a park on Sunday. Find the total number of boys and girls who visited the park?

46 + 27 = 40 + 20 + 6 + 7 = 60 + 6 + 7 = 66 + 7 = 73

4. 50 pens are in a box. Out of which, 34 pens are given to the students. Find the number of pens left?

50 – 34 = 16

5. 70 balls are given to 7 persons. How many balls are given to each person?

70 ÷ 7 = 10

6. 8 books can be arranged in a row. In how many rows can 48 books be arranged?

48 ÷ 8 = 6

7. 10 pens can be kept in a box. How many boxes are needed to keep 100 pens?

100 ÷ 10 = 10

Mastering Subtraction: Quick Tricks for 3rd Grade Maths

Quick Ways of Subtracting

3rd Maths | Term 3 Unit 7: Information Processing

We shall learn some tricks in subtraction also.

1. Using the Subtraction Table

We shall use the subtraction table to subtract small numbers.

2. Some Facts in Subtraction

Subtracting 0 from a number

A number remains the same when you subtract 0 from it.

Subtracting 1 from a number

When 1 is subtracted from a number, it gives a number before that number.

Subtracting 2 from a number

When 2 is Subtracted from a number, the numbers moves backward 2 steps.

Subtracting 10 from a number

When 10 is Subtracted from a number its ones place remains the same and digit in 10 place is decreased by 1 i.e., moves to the previous number.

3. Subtracting Same Numbers

Subtracting a number from itself will give the difference 0.

Example

Find the difference of 978−978 = 0

4. Subtracting Numbers Ending with 0

Subtract 1 from both numbers and then do the actual subtraction.

Example 1

Find the difference of 340 − 229

Example 2

Find the difference of 1000−574

As we subtract 1 from both the numbers the answer of the new numbers and question are same.

Practice Problems

Subtract the given numbers using the above facts.

3rd Maths Term 3 Unit 7: Information Processing - Quick Ways of Adding

3rd Maths : Term 3 Unit 7 : Information Processing

Quick Ways of adding

We perform addition of numbers in many situations daily. Let us learn some tricks which help us to add numbers quickly.

1. Using addition table is one of the good ways to add small numbers.

2. Let us know some facts in addition

i. Adding 0 to a number

A number remains the same when you add 0 to it.

ii. Adding 1 to a number

When 1 is added to a number it gives the at number.

iii. Adding 2 to a number

When 2 is added to a number the numbers jumps or skips over 2 next to it.

iv. Adding 10 to a number

When 10 is added to a number its ones place remains the same and digit in 10 place is increased by 1 i.e., moves to the next number.

3. Finding the pairs of 10

When a set of numbers are given to add, We shall find the pairs of numbers gives the sum 10 and add them.

Example

Find the sum of 7+4+6+3

7+3=10 and 6+4=10

Hence the sum of the numbers =10+10=20

Example

Find the sum of 5+3+2+6+4

6+4=10 and 5+3+2=10

Hence the sum = 10+10=20

Exercise

Find the sum of

(i) 5 + 1 + 5 + 9

(ii) 2 + 5 + 5 + 7 + 1

(iii) 3 + 6 + 1 + 2 + 8

i) 5 + 1 + 5 + 9

5 + 1 + 5 + 9

5 + 5 = 10 and 1 + 9 = 10

Hence the sum= 10+10=20

ii) 2 + 5 + 5 + 7 + 1

2 + 5 + 5 + 7 + 1

2+7+1=10 and 5+5=10

Hence the sum= 10+10=20

iii) 3 + 6 + 1 + 2 + 8

3 + 6 + 1 + 2 + 8

3+6+1=10 and 2+8=10

Hence the sum= 10+10=20

4. Doubling

(i) We shall double a number when we add the same number twice.

Example

5 + 5 = 2 × 5 = 10

7 + 7 = 2 × 7 = 14

(ii) We shall also use doubling when we add nearer numbers.

Example

5 + 6 = 2 × 5 + 1 = 10 + 1= 11

4+5 = 2 × 5 −1 = 10 −1 = 9

5. Adding two digit numbers

Add the ones and skip count the 10 s

Example

Find the sum of 7 + 12.

7 and 2 gives 9.

From 9 skip count in tens to get the sum 19.

7 + 2 = 9

9 + 10 = 19

Example

Find the sum of 25 + 33.

Adding ones 5 + 3 = 8

Skip counting 8 + 30 + 20 = 58

Example

Find the sum of 37 + 24.

Adding ones 7 + 4 = 11

Skip counting 11 + 30 + 20 = 61

6. Adding three digit numbers

Example

Find the sum of 576 + 323.

Suppose, We need add the following numbers, We shall follow these steps to add them quickly.

Step 1: Expand the number 500 + 70 + 6

300 + 20 + 3.

Step 2: Add the hundreds 500 + 300 = 800

Step 3: Add the tens one by one 800 + 70 = 870

870 + 20 = 890

Step 4: Add the ones by one 890 + 6 = 896

896 + 3 = 899

Add the given big numbers using the above method.

(i) 543 + 210

Step 1:
543 = 500 + 40 + 3
210 = 200 + 10

Step 2:
500 + 200 = 700

Step 3:
700 + 40 = 740
740 + 10 = 750

Step 4:
750 + 3 = 753

Answer: 753

(ii) 298 + 501

Step 1:
298 = 200 + 90 + 8
501 = 500 + 1

Step 2:
200 + 500 = 700

Step 3:
700 + 90 = 790

Step 4:
790 + 8 = 798
798 + 1 = 799

Answer: 799

(iii) 798 + 654

Step 1:
798 = 700 + 90 + 8
654 = 600 + 50 + 4

Step 2:
700 + 600 = 1300

Step 3:
1300 + 90 = 1390
1390 + 50 = 1440

Step 4:
1440 + 8 = 1448
1448 + 4 = 1452

Answer: 1452

(iv) 348 + 681

Step 1:
348 = 300 + 40 + 8
681 = 600 + 80 + 1

Step 2:
300 + 600 = 900

Step 3:
900 + 40 = 940
940 + 80 = 1020

Step 4:
1020 + 8 = 1028
1028 + 1 = 1029

Answer: 1029

(v) 543 + 218

Step 1:
543 = 500 + 40 + 3
218 = 200 + 10 + 8

Step 2:
500 + 200 = 700

Step 3:
700 + 40 = 740
740 + 10 = 750

Step 4:
750 + 3 = 753
753 + 8 = 761

Answer: 761

(vi) 716 + 540

Step 1:
716 = 700 + 10 + 6
540 = 500 + 40

Step 2:
700 + 500 = 1200

Step 3:
1200 + 10 = 1210
1210 + 40 = 1250

Step 4:
1250 + 6 = 1256

Answer: 1256

Cyclic Events in a Year: Understanding Time | 3rd Maths Term 3 Unit 6

3rd Maths : Term 3 Unit 6 : Time

Time cyclic events in a year

Every day we wake up in the morning and go to bed at night time.

This process keeps on repeating every day.

Every day the sun rises in the morning and sets in the evening .

Events that keep on repeating in the same manner (without much difference) refers a cycle.

Day and night occurs alternatively forms a cycle.

Some events like growth of a plant, construction of a house do not repeat. These events do not form a cycle.

Exercises

1. List the events that form a cycle and that do not form a cycle.

(i) Coming to school

(ii) Rotation of a clock

(iii) Days of a week

(iv) Growth of your pet

(v) Building your house

(vi) Making of idly

Solution

Events that from a cycle

1. Coming to school

2. Rotation of a clock

3. Days of a week

Events that do not form a cycle

1. Growth of your pet

2. Building your house

3. Making of idly

2. Complete the events of given cycle

(i)

(ii)

Activity

Preparing month cycle of a year.

* The Teacher can prepare cards with names of months.

* Divide the class into groups according to the strength.

* Give one set of cards to each group. Each set of cards should be shuffled.

* Ask the group to arrange the cards in the correct cycle of months. The group which completes the task first will be the winner.

Understanding Chronological Order | 3rd Grade Maths Term 3 Unit 6: Time

3rd Maths : Term 3 Unit 6 : Time

Time: Chronological Order

Chronological Order

Have you noticed your mother preparing idly. How does she prepare it.

(i) First, she soaks rice and black gram in water.

(ii) Second she grinds then to prepare a batter.

(iii) Third she ferments the batter overnight

(iv) Fourth she boils the batter to make idlies.

These events occur in an order in the process of making idly.

The method of arranging events in the order of their happening is called chronological order.

Example of arranging things in chronological order.

Historical event

Education qualification

Family tree

1. Write ‘F’ for the event which comes first and ‘N’ for the event which happens next.

(i) Eating (N) cooking (F)

(ii) Boarding into a bus or train (F) reaching the destination (N)

(iii) Drawing a picture (F) colouring (N)

(iv) Taking out a book from the bag (F) reading (N)

(v) Opening the door (F) Entering the room (N)

This is Kayalvizhi’s family

Chronological order of her family members is Grandfather, Grandmother, Father, Mother, Kayalvizhi, and her younger brother.

2. Arrange the following events in chronological order.

i. Started walking, birth, started schooling in class 1, studying in Class 3, studying in Class 2.

Birth

Started walking

Schooling in class 1

Studying in class 2

Studying in class 3

ii. Sowing seeds, plucking fruits, growing fruit, flowering in plant, watering plants.

Sowing seeds

Watering plants

Flowering in plant

Growing fruit

Plucking fruits

3. Write the names of the your family members in the chronological order.

Ask the birth years of your family members and arrange them chronologically.

(Grandfather Name)

(Grandmother Name)

(Father Name)

(Mother Name)

(your older brother/Sister)

(Your Name)

(your younger brother/Sister)

Understanding Time: A Guide to the Times of a Day | 3rd Maths Term 3 Unit 6

Chapter: 3rd Maths : Term 3 Unit 6 : Time

Times of a Day

UNIT − 6: TIME

Times of a Day

Look at the sky. Is it same all the time?

Sometimes the sun shines and sometimes the moon and the stars twinkle.

When the sun shines we call it day and when the moon and the stars twinkle we call it night.

12 hours of day time (sunlight) and 12 hours of night time (Darkness) comprises one day (24 hours).

1. Sort the events according to the time of happening

1. Sun rise

2. Sun set

3. Coming to school

4. Returning home from school

5. Breakfast

6. Dinner

7. Darkness outside

8. Say Good Morning

9. Say Good Evening

Understanding Rate Charts and Simple Bills | 3rd Grade Maths Money Lesson

Money: Rate Charts and Simple Bills

Introduction

Rate chart is seen in shops. Rate chart gives details about the rate of each item available in a shop. Bills are given by the shopkeepers to the customers as an acknowledgment of purchase. Bills give us complete details about the purchase.

Understanding Rate Charts and Bills

Rate Charts

Rate chart is seen in shops. Rate chart gives details about the rate of each item available in a shop.

Bills

Bills are given by the shopkeepers to the customers as an acknowledgment of purchase. Bills give us complete details about the purchase.

Observe the menu card.

Priya went to a restaurant and the waiter gave her a menu Card. The menu card showed the food items and the rate of each item.

Priya and her friend ordered the following items from the menu card.

Once she finished eating the waiter gave her the bill.

The bill shows the food items order by Priya and the total amount to be paid by her.

From the above bill, we come to know the following details:

i. Name of the Restaurant Hotel foods

ii. Bill number 25

iii. Date of the bill 30.10.2019

iv. Total number of items eaten 3

v. Total amount of money to be paid 20

vi. Rate of one idly 10

vii. Rate of one dosai 30

viii. Rate of one masala vadai 5

ix. Rate of two poori sets 90

Practice Exercises

1. The following are the items eaten by Raju and his family. Fill in the blanks using the given bill.

i. Name of the Restaurant HOTEL foods

ii. Bill number 32

iii. Date of the bill 30 . 10 . 2019

iv. Total number of items eaten 3

v. Total amount of money to be paid 310.

2. Complete the given bill and find the total amount to be paid.

3. Prepare Bills for the items purchased using the given rate chart.

i. Ramya bought two pens three erasers and a sketch packets. Prepare a bill for her purchase.

ii. Ravi bought an eraser a sharpener and two pens. Prepare a bill for his purchase.

Activity

Collect bills from different shops and prepare an album.

3rd Maths: Addition and Subtraction of Money | Term 3 Unit 5

3rd Maths: Term 3 Unit 5: Money

Exercise: Addition and Subtraction of Money

Question 1

Sengothai bought a school bag for ₹ 210.30 and a sports shoe for 260.20. Find the amount to be returned by the shopkeeper if she has paid five hundred rupees to the shopkeeper.

Adding Rupees

Cost of the bag = ₹ 210.30

Cost of sports shoe = ₹ 260.20

Total cost = ₹ 470.50

Subtracting Rupees

Sengothai paid = ₹ 500.00

Total cost = ₹ 470.00

Shopkeeper has to return = ₹ 30.00

Amount returned by shopkeeper to Sengothai = ₹ 30

Question 2

Kumaran’s father asked him to get a change for ₹ 200 from his uncle. If his uncle gave him a hundred rupee note and a fifty rupees note, how much more his uncle has to give him?

Adding Rupees

Uncle gave = ₹ 100

= ₹ 50

Total = ₹ 150

Subtracting Rupees

Father gave = ₹ 200.00

Uncle gave = ₹ 150.00

Uncle has to give him = ₹ 50.00

His uncle has to give him = ₹ 50

Mastering Money: Addition and Subtraction for 3rd Grade Maths (Term 3, Unit 5)

3rd Maths : Term 3 Unit 5 : Money

Addition and Subtraction of Money

Adding and subtracting money is as same as adding and subtracting numbers except that we place a dot to differentiate rupees and paise.

1. Add the following.

2. Subtract the following.

Usage of addition and subtraction of money in everyday situation

Kaarkuyil bought a hairclip for ₹. 20.50 and set of bangles for ₹ 30.50 and gave a one hundred rupees note to the shopkeeper the amount to be returned by the shopkeeper to Kaarkuyil.

(i) To find the total cost of the item bought add the cost of items bought.

(ii) Subtract the total cost of items from the amount (₹ 100.00) paid to the shopkeeper. This gives amount to be returned to kaarkuyil

Adding Rupees

Cost hair clip = 20.50

Cost of bangle = 30.50

Total cost = 51.00

Subtracting Rupees

Kaarkuyil paid = 100.00

Total cost = 51.00

Shop keeper has to return =   49.00

Amount return by the shopkeeper to Kaarkuyil = ₹ 49.00

Rupees and Paise Conversion: 3rd Maths Term 3 Unit 5 Money Explained

Money: Rupees and Paise

3rd Maths : Term 3 Unit 5

UNIT-5: Money

Rupees and Paise

We have learnt about currencies and coins of various denominations in our earlier classes. we shall learn the relation between rupees and paise addition and subtraction of money. We shall also learn about collection and preparation of bills.

1 Rupee = 100 paise

Some coins are given below.

These coins are outdated and currently not in use. But the value of paise is still used as digital value. Yet the value of paise in significant.

Conversion of Rupees into Paise

Now, let us see about conversion of rupees into paise.

1 rupee = 100 p

2 rupees = 2 × 100 p = 200 paise

5 rupees = 5 × 100 p = 500 paise

1. Convert the following rupees into paise.

Rupees Paise Rupees Paise

Know that

Mastering Measurement: Standard Tools and Units for 3rd Grade Maths

Measurements: Term 3 Unit 4

A lesson on measurement by standard tools for 3rd Grade Maths.

Measurement by standard tools

Meena & her mother

Mother : Meena! Pour one tumbler of water into the flour.

Meena : Ok, ma!

Mother : The batter is so thick. Did you pour one full tumbler of water?

Meena : Yes, ma!

Mother : Which tumbler did you use?

Meena : Ma, I used the small tumbler.

Mother : You have to use a bigger one.

Meena : Okay ma.

Mother : Meena! Now bring me 2 tumblers of water to pour in this milk.

Meena : Ma, I have brought water in big tumbler

Mother : Meena, now you should have brought water in the small tumbler.

Meena : Ma, Sometimes you ask me to bring water in big tumbler and sometimes small tumbler. I don't know when to bring in big tumbler and when to bring in small tumbler.

The Problem

What shall we do to find a solution for this issue?

We need a standard tool to measure capacities of containers. We also need a standard unit to express capacities of containers.

Standard Tools for Measurement

These are some Standard tools to measure capacity. You can find them in milk shops, grocery shops, etc., We measure liquids such as water, oil, milk, petrol., using these tools.

Standard units for measuring capacity of a container is litre.

* We measure liquids smaller containers using millilitres.

* We measure the liquids of more quantity /capacity of bigger containers using litres.

Activity

1. Teacher can conduct the game, fill in the bottle.

2. Teacher can conduct a mock milk shop in the class.

Exercise 1: Classifying Vessels

1. Complete the table classifying these under the given table.

Answers

Less than 1 litre vessel

1. Medicine bottle

2. Tumbler

3. Water pot

More than 1 litre vessel

1. Pot

2. Oil can

3. Water can

Exercise 2: Tick the Unit

2. Tick the appropriate unit to measure the given liquid.

Exercise 3 & 4: Biggest and Smallest Units

3. Tick / underline the biggest unit

i. a) 500 ml b) 100 ml c) 50 ml d) 75 ml

ii. a) 200 ml b) 300 ml c) 150 ml d) 175 ml

iii. a) 5 l b) 2 l c) 8 l d) 7 l

iv. a) 3 l b) 300 ml c) 30 ml d) 30 l

v. a) 250 ml b) 1500 ml c) 760 ml d) 75 l

4. Circle/ underline the smallest unit

i. a) 250 ml b) 350 ml c) 50 ml d) 750 ml

ii. a) 300 ml b) 350 ml c) 800 ml d) 275 ml

iii. a) 10 l b) 3 l c) 9 l d) 6 l

iv. a) 3 l b)350ml c) 5 ml d) 40 l

v.a) 2500 ml b) 100 ml c) 810 ml d) 175 l

Exercise 5: Daily Water Usage

5. How many litres of water do you use for the following purpose in your house? Complete the table.

Exercise 6: Measuring Containers

6. How many litres are needed for filing the given containers. Complete the table by measuring the containers by one litre bottle.

Answers

Bottle 1 1 litre bottles

Bucket 20 1 litre bottles

Pot 40 1 litre bottles

Activity

Take a 1 litre bottle and a tumbler fill the bottle using it.

How many times did you use the tumbler for filling the bottle ?

4 times

Repeat the same activity using different containers (Cups, tumblers, bottles ) and record you findings.

1. Which container was used twice?

Cups

2. Which container was used four times?

Tumblers

3rd Maths: Term 3 Unit 4 - Measurement by Non-Standard Tools

Measurement by non standard tools

3rd Maths : Term 3 Unit 4 : Measurements

Measurement by non standard tools

can hold 3 tumblers of water. So, the capacity of is equal to 3 tumblers. can hold 5 tumblers of water. So, the capacity of is 5 tumblers. can hold 10 tumblers of Water. So, the capacity of is 10 tumblers.

1. Tick the container that holds more water.

2. Which among the given container will hold more water?

Activity

3. a. Measure using and complete the data.

3. b. Arrange the vessels given above by their capacity from less water to the vessels with more water by writing the names in the blanks.

1. Water bottle

2. Water drum

3. Steel pot

4. Plastic pot

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3rd Maths Term 3 Unit 4 Measurements non standard tools Samacheer Kalvi

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