1.9 To recognise numbers and compare them to one another

Mathematics

Number concept, addition and subtraction

Educator section

Memorandum

1.

1.1 8 366

1.2 7 452

1.3 8 664

1.4 9 548

2.

2.1 6 750

2.2 8 260

2.3 3 516

2.4 9 379

3.

3.1<

3.2<

3.3<

3.4<

Answer on p. 11-12

1. 46

2. 26

3. 39 337

4. 5 000 I)

5. 4 072 j)

6. 4 440

7. 7 739

8. =

9. 14; 5

10. 1 000; 8

Leaner section

Content

Activity: to recognise numbers and compare them to one another [lo 1.3]

To be able to calculate correctly [lo 1.8]

MORE OR LESS?

1. If you know where the tens and hundreds are in a number (place value) it is easy to add 10 or 100 (more than), or subtract 10 or 100 (less than). See whether you can write down the answer immediately! Which number is:

1.1 10 more than 8 356?_____________________________________________

1.2 10 less than 7 462? ______________________________________________

1.3 100 more than 8 564? ____________________________________________

1.4 100 less than 9 648? _____________________________________________

2. In this activity you must read the question carefully and compare your answer to the given number to ensure that you have worked correctly.

2.1 6 740 is 10 less than _____________________________________________

• 8 360 is 100 more than ____________________________________________

2.3 3 526 is 10 more than _____________________________________________

2.4 9 279 is 100 less than _____________________________________________

Note: "less than" now means that you must add to get the right answer, and "more than" means that you must subtract to calculate the answer!

COMPARING AND ARRANGING

Do you remember this?

>means "larger than"

<means "smaller than"

= means "equal to" or "the same as"

3. We can use the mathematical symbols<;>and = when we compare answers. It is important that you calculate the answer correctly, or the symbol will be wrong! Now calculate the answer where necessary, compare the answer left of the é wit the one right of the é and then complete:<;>or =:

3.1 (5 × 6) + 9 * 41

3.2 8 921 * 9 821

3.3 2 356 * 2 000 + 500 + 30 + 6

3.4 4 000 + 200 + 50 + 7 * 4 275

FUN WITH THE POCKET CALCULATOR!

Work with a friend. You will need one pocket calculator.

• Player A types in any four-digit number on the pocket calculator, e.g. 4 986.
• Player B now "shoots down” any of the figures by means of subtraction, e.g. 4 986 − 80 = 4 906.
• Take turns to "shoot down” figures. The winner is the player who gets 0 on the display screen.

ASSESS YOURSELF BEFORE GOING FURTHER!

Complete the following by marking the applicable column only:

LET US SEE HOW YOU ARE COPING.

• Are you able to answer the following questions correctly?

1. How many hundreds are in 4 600?___________________________________

2. How many thousands are in 26 000? _________________________________

3. Encircle all the odd numbers in the following:

14 ; 39 ; 128 ; 337 ; 4 000

4. What is the value of the 5 in 5 713?__________________________________

5. Which number is represented in the following diagram?

6. Encircle the largest number:

4 040 ; 4 404 ; 4 440 ; 4 004

7. Which number is 100 more than 7 639?_______________________________

8. Fill in>;<of = :

40 + 200 + 3 000 + 6 ____________________ 3 246

9. Complete the pattern:

41 ; 32 ; 23 __________________ ; __________________

10. Complete:

2 386 = (2 × _________) + (3 × 100) + (_________ × 10) + (6 × 1)

Assessment

Learning Outcome 1: The learner will be able to recognise, describe and represent numbers and their relationships, and to count, estimate, calculate and check with competence and confidence in solving problems.

Assessment Standard 1.3: We know this when the learner recognises and represents numbers in order to describe and compare them:

Assessment Standard 1.8: We know this when the learner estimates and calculates by selecting and using operations appropriate to solving problems.