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### Transcript of Kungfu math p4 slide1 (numbers up to 100000) pdf

• number notation and place values (ten thousands, thousands, hundreds, tens, ones)

rounding off numbers to the nearest

10 or 100

use of the approximation

symbol ()

What will we learn today?

Whole Numbers Numbers up to 100 000

• Understanding the place values

• Before we begin, lets understand what is place values.

• In the number 1245,

tens ones

• In the number 1245,

thousands hundreds

• 81245

thousands hundreds

In a 5 digit number

• ten thousands

In a 5 digit number

81245

• So, in a 5-digit number,

There are

Ten thousands place

Thousands place

Hundreds place

Tens place

Ones place

• Heres an example.

• In 9265, the digit 2 is in the ___ place.

a) ones

b) tens

c) hundreds

d) thousands

• In 9265, the digit 2 is in the ___ place.

a) ones

b) tens

c) hundreds

d) thousands

The 2 stands for 200.

• In 9265, the digit 2 is in the ___ place.

a) ones

b) tens

c) hundreds

d) thousands

• Heres another example.

• In 27501, the digit 5 stands for _____.

a) 5

b) 50

c) 500

d) 5000

• In 27501, the digit 5 stands for _____.

a) 5

b) 50

c) 500

d) 5000

The 5 is in the hundreds place.

• In 27501, the digit 5 stands for _____.

a) 5

b) 50

c) 500

d) 5000

The 5 stands for 500.

• rounding off numbers to the nearest 10 or 100, and learn the use of the approximation symbol ()

Lets try:

• Rounding off Numbers

Look at the digit to the right of the required place value.

If the digit is less than 5,

round down.

If the digit is 5 or more,

round up.

• Try this out!

Round off 483 to the nearest hundred.

• Solution

1) Round off 483 to the nearest hundred. Answer:500 (8 is more than 5 so we round up)

To round off a number correct to a given place, we round up (that is add 1) if the next figure is 5 or more, we round down (that is just drop them) if the next number is less than 5.

• Heres an example.

• Try this out!

Round off 314 to the nearest hundred.

• Try this out!

Round off 314 to the nearest hundred.

3 | 14 300

1 is less than 5, so we just drop 14. That is why we round down to 300.

• You have done a great job! Lets move on!

• What is the best estimate for 589 x 61 ?

(1) 500 x 60

(2) 500 x 70

(3) 600 x 60

(4) 600 x 70

• What is the best estimate for 589 x 61 ?

(1) 500 x 60

(2) 500 x 70

(3) 600 x 60

(4) 600 x 70

589 600

Lets try rounding off the number.

• What is the best estimate for 589 x 61 ?

(1) 500 x 60

(2) 500 x 70

(3) 600 x 60

(4) 600 x 70

61 60

Lets try rounding off the number.

• What is the best estimate for 589 x 61 ?

(1) 500 x 60

(2) 500 x 70

(3) 600 x 60

(4) 600 x 70

589 600

61 60

• What is the best estimate for 589 x 61 ?

(1) 500 x 60

(2) 500 x 70

(3) 600 x 60

(4) 600 x 70