Grade Six Mathematics
Answers to last week’s questions Exercise 1
a) Total number of customers = 106 b)
I. 25.5% (to 1 decimal place)
II. 32.1% (to 1 decimal place)
III. 29.2% (to 1 decimal place)
IV. 13.2% (to 1 decimal place) c ) A total of 54.7% of customers prefer nachos
and ice cream. d) 20 customers prefer cheese fries to yogurt.
Hello Boys and Girls,
Welcome back to our Mathematics Corner. In our previous session, we explored pie charts, determining percentages and degrees from numerical data. This week, our focus shifts to a new subject: ‘Approximation’ or ‘Rounding whole numbers. Let us begin…
Approximation/ Rounding off whole numbers
What is an approximation?
An approximation is anything that is close, but not exactly equal, to something else. For instance, a number can be approximated by rounding, which involves expressing it as a nearby value that may be slightly higher or lower than the original. Whole numbers can be approximated to the nearest tens, hundreds, thousands, and so forth.
The symbol ≈ means approximately equal to.
Ok boys and girls, now that we’ve grasped the concept of approximation, let’s delve into exploring a few practical exercises.
Approximating to the nearest tens
We would’ve learned that rounding can be done for every place value of a number. However, to round off a number to the nearest tens, we round off to the nearest multiple of ten.
Now, how do we go about doing that? Let us examine the steps in doing so:
Steps for rounding off to the nearest tens
Step 1- Underline the tens digit.
Step 2- If the Ones digit is less than 5, that is; if the Ones digit is (4,3,2,1) the Tens digit remains the same and 0 replaces the Ones digit. E.g. 252 ≈ 250
Step 3- If the Ones digit is (5,6,7,8,9) add (1) to the Tens digit and write a zero to replace the
Ones digit. E.g. 447 ≈ 450.
N.B:
If the tens digit is 9, then 1 is added to the Hundreds digit. E.g. 897 ≈ 900
Additional examples: a. 234 ≈ 230 b. 377 ≈ 380 c. 896 ≈ 900
Complete the exercise below. above as a guide) (Use the steps
Exercise 1
Approximate the following numbers to the nearest Tens:
1. 91 2. 54 3. 75 4. 22 5. 87 6. 736 7. 937 8. 846 9. 284
10. 444
Excellent work, students! Let’s move on.
Approximating to the nearest hundreds
Step 1: Underline the
Hundreds Digit.
Step 2: If the Tens digit is less than 5, that is; if the digit is (4, 3, 2, 1), the Hundreds digit remains the same and 0 replaces the Tens and Ones digits. E.g. 435 ≈ 400.
Step 3: If the Tens digit is (5,6,7,8,9) add 1 to the Hundreds digit and write zero to replace the Tens and Ones digits. E.g. 575 ≈ 600.
N.B: If the Hundreds digit is 9, then 1 is added to the Thousands digit and write zero to replace the Hundreds, tens and ones digits. E.g. 2974 ≈ 3000.
Here are some additional Examples: a. 534 ≈ 500 b. 375 ≈ 400 ≈ 4000
Now students, here’s your opportunity to work some on your own. Keep in mind the steps we’ve previously discussed.
Exercise 2
c. 3975
Approximate the following numbers to the nearest Hundreds:
1. 946 2. 836 3. 4746 4. 4836 5. 256 6. 974 7. 8464 8. 873 9. 937
10. 999 Great job!
Did you know that we can also round numbers to the nearest thousand? Indeed, we can! Let’s explore how to do it.
Approximating to the Nearest Thousands
-To round to the nearest thousand, we look at the last three digits.
-If these digits are 500 or greater, then we round the Thousands digit up (add 1 to the Thousands digit and write zero to replace the Hundreds, Tens and Ones digits. E.g. 4675 ≈ 5000.
-If the digits are less than 500, then we round down, keeping the thousand’s digit the same, replacing the Hundreds, Tens and Ones digits. E.g. 7332 ≈ 7000
-If the Thousands digit is 9, then 1 is added to the Ten thousands digit. E.g. 39763 ≈ 40,000
Now boys and girls, I want you to apply the knowledge you have gained by completing the exercise below:
Exercise 3
Approximate the following numbers to the nearest Thousands:
1. 3746 2. 8947 3. 8364 4. 5432 5. 1237 6. 9387 7. 3578 8. 7363 9. 1456
10.2772
That wraps up today’s session, boys and girls. I appreciate your attentiveness. Looking forward to sharing the answers to this week’s problems when we reconvene next week. Wishing you all a fruitful week ahead in your studies. Take care Boys and Girls!