UNIT : 8 SHAPES AROUND US. A point has no length, breadth, height or shape. It only has a position.

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1 UNIT : 8 SHAPES AROUND US Explain straight line, curved lines, basic shapes and solid shapes. Roll back : Qn. 1,2,3 (Do in T.B) Point We can plot a point on a paper by putting a dot by a sharp pencil. This dot is called a point. A point has no length, breadth, height or shape. It only has a position. Each vertex (corner) defines a point. A point is always denoted by a capital letter. Eg. P ( point P ) X ( point X ) Y (point Y ) Line Segment If we join two points with ruler, we get a line segment. A part of straight line joining two points is called a line segment. Each edge defines a line segment, Line segment AB is denoted as AB Eg. Note Line segment is the shortest path between two points. Ray as AB. If we extend a line segment in one direction indefinitely, we get a ray. We denote a ray AB Eg. ( AB ) ( XY ) Line If we extend a line segment in both directions indefinitely, we get a line. Line AB is denoted as AB, where A and B as any two points on the line. Eg.

2 Difference between Line, Line segment and Ray Line Line Segment Ray It has two end points. It cannot be extended. 1) It has no end point. 2) It can be extended indefinitely on both sides. 3) It has no fixed length. 4) It is denoted as AB, where A And B are any two points on the line. Ex : 1. Qn : 1,2,3. ( Do in note book ) Measuring Length It has a fixed length. It is denoted as AB It has one end point. It can be extended indefinitely On one side. It has no fixed length. It is denoted as AB rod etc. Length can be measured by using different tools such as a ruler, a measuring tape, a metre The ruler is marked with smaller and bigger divisions. The smaller divisions are called millimeters and the bigger divisions are called centimeters. 1 cm = 10 mm Ex. 1 Qn : 5, 6 and Let us revise Qn : 2 (Do in TB) Curves Polygon Simple closed curve is a closed shape that does not cross itself. Closed shapes formed with line segments are called polygons. Ex : 2. Qn : 1, 2, 3 ( Do in TB ) Types of Polygons A polygon has minimum 3 sides. A polygon with 3 sides is called a triangle. A polygon with 4 sides is called a quadrilateral. Note Rectangle is a special type of quadrilateral in which opposite sides are equal. Square is a special type of quadrilateral in which all sides are equal. Ex. 3 Qn : 1,2 (Do in TB ) and Let us Revise 3, 4, 5. Project : Making mask using basic shapes.

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4 UNIT-1 Numbers and Numeration All numbers from 1,2,3,4,5.are called Natural numbers.(counting numbers) If 0 (zero) is included in natural numbers, they become a set of Whole numbers. 1 to 9 are 1-digit numbers. 10 to 99 are 2-digit numbers. 100 to 999 are 3-digit numbers to 9999 are 4=digit numbers. 5-digit numbers When we add 1 to the greatest 4-digit number, we get the smallest 5-digit number = (read it as Ten Thousand) A 5-digit number begins with the ten thousands place. Write all no: from a) to ( c w ) b) to (c w ) c) to ( H w ) 6-digit numbers When we add 1 to the greatest 5-digit number, we get the smallest 6-digit number = (read it as Lakh) A 6-digit number begins with the lakhs place. Write all no: from a) to b) to Digits Smallest Greatest One digit 1 9 Two digit Three digit Four digit Five digit Six digit

5 Place value chart. Lakhs period Thousands Period Ones Period Ten Lakhs Lakhs Ten Thousands Thousands Hundreds Tens Ones The ones period has three places- hundreds, tens and ones. The thousands period has two places- ten thousands and thousands. The lakhs period has two places- ten lakhs and lakhs. Note: When we write a number without using a place value chart, we use comma to separate the periods. Exercise : 1 Qn : 1,2.3.5 and 6 ( In note book ) Face value and place value The face value of a digit is always the digit itself. The place value of a digit = Its face value x value of the place. The place value and face value of zero is always zero. Note: Successor = number+ 1. Predecessor = number 1. Give example. Exercise : 1 Qn : and 14 ( In note book ) Comparison of numbers. (explain case 1 and case 2 and give examples ) Exercise : 2 Qn : and 4 ( in note book ) Number formation To form the greatest number, rearrange the digits in decreasing order. To form the smallest number, rearrange the digit in increasing order. We don t write o in the beginning of a number because it has no value. So it will occupy 2 nd place from the left. Give an example Exercise : 3 Qn : 1 ( In note book ) Assignment : Page No , Let us revise

6 UNIT 2 ADDITION AND SUBTRACTION OF LARGE NUMBERS ADDITION FACTS (EXPLAIN IN THE CLASS) 1. We can change the order of two numbers when finding their answer eg: = = We can change the grouping of three numbers when finding their answer eg: (25 +32) + 31 = 25+ (32 +31) = = If zero is added to a number, its value remains the same eg: 235+0=235 and 0+235= The successor of a number=number +1 eg: 99+1=100 FILL IN THE BLANKS (addition and subtraction) = = = = = = = = = = = ADDITION Note : The numbers to be added are called addends. The answer of addition is called the sum : eg:

7 Always write ones under ones, tens under tens and so on. Page no: 27 & 28 Try these, do in the text book. ADD THE FOLLOWING Page no 28: EX 1, qn no: a, c, e, g, i, k do as CW Qn no: b, d, f, h, j, l do as HW. WRITE IN COLUMNS AND ADD a) 31,764, 2,384, and 2,961 ans: (b) 42,896, 1,10,794 and 8,276 = (c) 3,846, 1,956 and 3,876 = 9678 (d) 13,942, 2,651 and 1,004 = ANSWER THE FOLLOWING QUESTIONS (a) In a town, there are 76,843 men, 57,698 women and 10,423 children, What is the total population of the town? Ans : 1,44,964 (b) A Delhi library has 6,964 books of English and 3,656 books of Hindi. How many books are there in the library? Ans : 10,620 (c) A dairy sold 5,079 litres, 3,034 litres and 14,412 litres milk in three months. How much milk did the dairy sell in three months? Ans : 22,525 (d) A cloth mill produced 96,840m of cloth in first week, 29,060 m of cloth in second week and 27,408 m of cloth in third week. What length of cloth was produced in three weeks? Ans : 1,53,308 (e) Find the sum of the greatest 3-digit, 4-digit and 5-digit numbers? Ans : 1,10997 HW Page no:29 Exercise 1,Qn no;4 (c,d) SUBTRACTION Note :- The number from which we subtract another number is called the minuend. The number to be subtracted is called. Subtrahend, The answer of subtraction is called the difference. Eg : 6948 Minuend Subtrahend 3321 difference Page no 30 ; Try these do in the text book

8 SUBTRACT THE FOLLOWING. Ex:2, Qn no:1 ; a, c, e, g, i, k do as CW. Qn no: b, d, f, h, j, l do as HW WRITE IN COLUMNS AND FIND THE DIFFERENCE (a) 12,790 from 25, (b) 24,387 from 61,231 = 36,844 (c) 10,987 from 5,07,432 = 4,96,445 (d) 2,531 from 62,953 = 60,422 ANSWER THE FOLLOWING QUESTIONS(WORD PROBLEM) (a) The total number of buses and cars in a state are 46,432. If the number of buses is 4,587 then find the number of cars? Ans : 11,845 (b) The sum of two numbers is 65,431. If the greater number is 39,576 then find the smaller number? Ans : 25,855 (c) A company had 2,671 number of workers. If 2,186 workers are transferred to another company then how many workers are left in the previous company? Ans : 485 (d) A factory produced 58,475 packets of biscuits in a week. In the next week it produced only 13, 176 packets due to absence of workers. Find the difference of number of packets of second week from the first week? Ans : 45,299 (e) what must be added to 1,459 to get 3,504 HW PAGE NO 32 EXERCISE 2 QN NO 4 (B, C, E) ASSIGNMENT LET US REVISE (PAGE NO: 35) Qn no: 1, 4 (c,d) and 5.

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10 UNIT 3 MULTIPLICATION I Revise multiplication table II Properties of multiplication 1. Any number multliplied by 1 we get the number itself. 2. Any number multliped by 0 we get zero. 3. We can change the order of factor, the product remains the same. 4. Multiplication is repeated addition when all the addends are same. Fill in the blank: a) 32 x 1 = b) 28 x 0 = c) 88 x = 88 d) x 51 = 0 e) = x 7. III Terms associated with multiplication : 1. The numbers that being multiplied are called factors. 2. The answer of multiplication is called product. 123 factors X3 369 Product IV Multiply by one digit number: Try these a, b ( pg. no - 43) i) a) x 5 b) 3917 x 8 c) 3896 x 3 ii) Try these (pg no. 41) do in T. B. iii) Ex. 1 Qn. No. 1 ( a f) H. W (g l). iv) Ex. 1 Qn. No. 2 (a c) H.W (d, e). V Multiplying by a 2 digit number. a) Multiplying by 10, 20, 30 etc. To multiply any number by tens, multiply the factors without zero of tens then write the zero on the right of the product. Fill in the blanks a) 5 x 10 = b) 254 x 10 = c) 8 x = 80 d) 4 x 30 = e) x 20 = 160. Try these pg. no. 43 (a, b) do in T.B.

11 Multiply 273 x 45 ; 1264 x 16 Ex. 2 Qn. 1 ( a,b, e, f, I, j, m, n, q, r) H.W (c,g,k,o,s) (d, h, l, p,t) practice at home. VI Multiplying by a 2 digit number. a) Multiplying by 100, 200, 300 etc. To multiply any number by hundreds, multiply the factors without zeros of hundreds then write two zeros on the right of the product. Fill in the blanks: a) 25 x 100 = b) 87 x 200 = c) x 100 = 5300 d) 2 x 300 =. Ex. 2 : Qn.No.2 c.w ( a,b, e,f, I, j, m,n) H.W (c,g,k,o) (d, h, l, p) Practice at home. VII Answer the following Ex. 2 Q. No. 3. Assignment : pg No. 51 Activity : Prepared by Mrs. U. Nagarathinam xxxxxxxxxx

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13 MULTIPLICATION Questions for low achiever:- 1) 5 x 10 = 2) 26 x 1000 = 3) 122 x 2 = 4) 111 x 888 = Questions for high achievers:- 1) 25 x 800 = 2) 564 x 187 = 3)