Mathematics
Number concept
Educator section
Memorandum
1. Look at the tenth didgit. If 5 or more, add one to hundreth number. If 4 or less the hundreth number stays the same. Replace tenth and one-numbers with nought.
2. hundreds
thousands add one
hundreds, tens and ones
3.1 8 000 8 000
3.2 47 200 47 000
3.3 150 500 151 000
3.4 3 409 200 3 409 000
3.5 5 631 000 5 631 000
Brain teaser
i) R90 000
ii) R14 000
Leaner section
Content
Activity: to calculate by selecting appropriate operations for solving problems[lo 1.8.1]
1. In Grade 5 we saw repeatedly how important it was to round off correctly. Amongst other things, it can help us to estimate an answer quickly, without using pencil and paper.
Rounding off
- Let's revise
- Explain to your friend how we round off to the nearest 100.
2. Try to complete the following on your own:
If you are unable to do it on your own, ask a friend to help you!
3. Complete the following table:
number | rounded off to the nearest 100 | rounded off to the nearest 1 000 | |
3.1 | 7 995 | ||
3.2 | 47 216 | ||
3.3 | 150 505 | ||
3.4 | 3 409 235 | ||
3.5 | 5 630 981 |
Puzzle!
- Can you round off the following to the nearest 10 000?
i) __________________________________________________________________
Price R89 895
ii) __________________________________________________________________
Price R13 995
TIME FOR SELF-ASSESSMENT
How well do you understand the preceding work? Assess yourself on a scale of 1 to 4. Circle the appropriate code:
1 = needs attention
2 = fairly good
3 = very good
4 = excellent
Criteria: | Code | |||
I can read 7-digit numbers correctly. (LO 1.3) | 1 | 2 | 3 | 4 |
I can write 7-digit numbers correctly in words. (LO 1.3) | 1 | 2 | 3 | 4 |
I am able to determine the value of digits in a number correctly. (LO 1.4) | 1 | 2 | 3 | 4 |
I understand the powers of 10 and can use them correctly. (LO 1.10) | 1 | 2 | 3 | 4 |
I can round off correctly to the nearest 100. (LO 1.8) | 1 | 2 | 3 | 4 |
I can round off correctly to the nearest 1 000. (LO 1.8) | 1 | 2 | 3 | 4 |
I can round off correctly to the nearest 10 000. (LO 1.8) | 1 | 2 | 3 | 4 |
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 1.8: We know this when the learner estimates and calculates by selecting and using operations appropriate to solving problems that involve:
1.8.1: rounding off to the nearest 5, 10, 100 or 1 000.