LENHAM PRIMARY SCHOOL GRADE 5: MATHS - WEEK 3

LENHAM PRIMARY SCHOOLGRADE 5: MATHS - WEEK 3TOPIC: MULTIPLICATION1.a)d)g)Mental test (Complete in 1 minute)100 x 1 b) 15 x 1 26 x 0 e) 26 x 10 26 x 1 000 h) 26 x 20 2.a)b)c)d)c) 998 x 1 f) 26 x 100 i) 26 x 200 COMPLETE PAGE 128 no. 1 OF YOUR BLUE BOOK.Complete the next 4 multiples of:2505001 0001 500* COMPLETE PAGE 128 no. 2a-e OF YOUR BLUE BOOK.3. ESTIMATE the answers by rounding off to the nearest 10.eg. 35 x 21 40 x 20 800a) 47 x 32 x b) 29 x 46 x c) 143 x 21 x d) 435 x 23 x 4. BREAKING up numbersExample:125 x 31 125 x (30 1) . break up the smaller number into tens and units. (125 x 30) (125 x 1) 3 750 125 3 875Use the BREAK UP METHOD to complete the following calculations. Follow the above example.a) 214 x 22 b) 321 x 15 1

The breaking up method can also be arranged VERTICALLY. Study the example below.125 x 31:125x 31125 (125 x 1) 3 750 (125 x 30) . don t forget the MAGIC ZERO.3 850Complete the following examples using the vertical method.a) 2 1 4x22( ( b)xx))321x 15( (xx))Complete pages 129 and 130 in your blue book.5. DOUBLING and HALVINGThis means multiplying one number by 2, and dividing the next number by 2.eg. 24 x 12 48 x 6 96 x 3 288Multiply the following numbers using the doubling and halving method, as above.a) 150 x 8b) 210 x 66.a)c)e)g)Use the column method to multiply. (complete this exercise in your jotters.)235 x 5b) 145 x 6426 x 12d) 659 x 14321 x 23f) 562 x 31824 x 36h) 721 x 427. MultiplesCopy and complete these multiple tables246834521012

6102025 Complete pages 134 and 135 of your blue books8. FactorsTo find a pair of factors, divide each number by a whole number. If there is no remainder then you havefound a pair of factors. Always start dividing by 1, then 2, etc.Example 1. Factors of 6 ( we write as: F6)1 x 62 x 3Factors of 6 1, 2, 3, 6 (arrange factors from smallest to biggest).Example 2: Factors of 15 (F15)1 x 153 x 5Factors of 15 1, 3, 5, 158.1 Find the factors of the following numbers:a) F14b) F25F14 F25 c) F30F30 d) F60F60 Complete pages 136 and 137 of your blue books.3

9. Properties of whole numbers (multiplication)9.1 Commutative propertyThe order of the numbers can change but the product (answer to a multiplication sum), will remain thesame. eg. 2 x 4 4 x 2 8Change the order of the numbers to get the same answer. Follow the given example.a) 12 x 5 b) 8 x 12 c) 11 x 10 d) 12 x 10 e) 15 x 12 9.2 Associative propertyWhen multiplying, numbers can be grouped in any order, the product remains the same.LHSRHSeg. (3 x 6) x 10 3 x (6 x 10) . . . . . . The left hand side (LHS) the right hand side (RHS)18 x 10 3 x 60180 180Complete by changing the brackets or regrouping and find the answer.a) (5 x 8) x 2 b) (3 x 10) x 2 c) (9 x 5) x 1 d) (7 x 3) x 3 9.3 Distributive propertyExample: 215 x 24Step 1: Break up the 24 into tens and units: 20 4 215 x (20 4) (215 x 20) (215 x 4) 4300 860 5 160Work out the following exercise using the method above. Work in your jottersa) 156 x 25b) 214 x 28c) 278 x 24d) 254 x 42 Complete pages 138 to 141 of your blue book.10. Calculate the following in 1 minutea) 66 x 1 b) 87 x 1 d) 672 x 0 e) 66 x 0 g) 350 x 0 h) 286 x 0 4c) 350 x 1 f) 87 x 0 i) 0 x 1

11. Revision of vertical multiplication11.1 2 digits by 1 digit1a) 5 3x 4212Step 1: 3 x 4 122. Write 2 in the units column. Carry 1 to the tens column.3. 5 x 4 1 21.12b)28x 8c)36x 4d) 32x 711.2 3 digit by 1 digit1 1a)b)154x3462Step 1. 4 x 3 122. Write 2 in unit s column. Carry 1 to the ten s column.3. 5 x 3 1 16. Write 6 in the ten s column. Carry 1 to hundred s column.4. 1 x 3 1 4228x8c) 2 3 6x4d) 5 3 2x711.3 2 digit by 2 digita)16x 123 2 (16 x 2) 1 6 0 (16 x 10) .Magic 019 2b)24x 15(24 x 5) (24 x 10)c) 6 4x 13(64 x 3) (64 x 10)d) 2 3x 19(23 x 9) (23 x 10)11.4 3 digit by 2 digita) 1 5 4x 23(154 X 3) (154 X 20)b) 1 3 8x15(138 X 5) ( 138 X 10)c) 3 0 6x 32(306 X 2) (306 X 3)5

12. Problem solvingSteps: 1. READ the problem a few times to get an understanding of it.2. CIRCLE the important numbers.3. DECIDE what operation to use to solve the problem.4. WORK out the problem and answer the question.Use the 3 steps to solve the following problems:a) Open number sentence.b) Workingc) Word sentence12.1 Mr. Harris bought 145m of wire to fence his vegetable garden. Mr. Khumalo bought 12 times asmuch wire. How many metres of wire did Mr. Khumalo buy?a) open number sentence:b) working:() ()c) Mr. Khumalo .12.2 Mrs. Chetty has 125m of material. I have 4 times as much material. How much material do Ihave?a) open number sentence:b) working:xc) I have .13. Rateeg. The car travels at 100km per hour. Km per hour is called the rate. The shortened form is:100km/h . . . . . . . / means PER or for EACH ONE.a) A car travels at 120km/h. How far will it travel in 5 hours?Answer: 120 x 5 600 km*COMPLETE PAGES 132 AND 133 OF YOUR BLUE BOOK.6

found a pair of factors. Always start dividing by 1, then 2, etc. Example 1. Factors of 6 ( we write as: F6) 1 x 6 2 x 3 Factors of 6 1, 2, 3, 6 (arrange factors from smallest to biggest). Example 2: Factors of 15 (F15) 1 x 15 3 x 5 Factors of 15 1, 3, 5, 15 8.