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Kelly has $25 439 in her savings account. What is this amount in words?

Ten

ThousandsThousandsHundredsTensOnes25439twenty five thousandfour hundredandthirty nine

So, in words, Kelly hastwenty five thousand, four hundred and thirty ninedollars in her savings account.

Find the place and value of each digit in the number 25 439.

25439Ten Thousands Thousands Hundreds Tens Ones × 10 000 × 1000 × 100 × 10 × 1

In 25 439,

- the digit 9 is in the
onesplace, its value is 9 × 1 or9- the digit 3 is in the
tensplace, its value is 3 × 10 or30- the digit 4 is in the
hundredsplace, its value is 4 × 100 or400- the digit 5 is in the
thousandsplace, its value is 5 × 1000 or5000- the digit 2 is in the
ten thousandsplace, its value is 2 × 10 000 or20 000

How do you write sixty thousand and twenty three in figures?

sixty thousandtwenty three60023Ten Thousands Thousands Hundreds Tens Ones

sixty thousand= 60 × 1000= 60 000 twenty three = 23 × 1= 23 sixty thousand and twenty three = 60 000 + 23 = 60 023

In figures, sixty thousand and twenty three is60 023.

How many hundreds are there in 36 000?

Ten

ThousandsThousandsHundredsTensOnes3 6 0 0 0

Hundred

HundredsTen

HundredsHundredsTensOnes3 6 0 0 0

36 000 = 360 00= 360 hundreds

There are 360 hundreds in 36 000.

There are three hundred and sixty hundreds in thirty six thousand.

Compare the numbers 37 261, 38 412 and 37 265.

- Which number is the smallest?
- Which number is the biggest?
- Arrange the numbers in order, beginning with the smallest.

Ten

ThousandsThousandsHundredsTensOnes37 2613 7 2 6 1 38 4123 8 4 1 2 37 2653 7 2 6 5

Compare the numbers digit by digit starting with the digit in the highest place value.

- 37 261 is the smallest number
- 38 412 is the biggest number
- 37 261, 37 265, 38 412

Complete the number patterns below.

- 600, 725, _______, 975, ________, 1225
- 45 554, 46 554, 46 454, 47 454, 47 354, ________, ________, 49 254

Rule:Add 125 to get the next number.

Rule:Add 1000 and subtract 100 alternately to continue the number pattern.

Rounding off or approximation means to simplify numbers so they are easy to use and remember.

Rounding off to the nearest ten

Joyce bought a pair of shoes for $38.

Weround up38 to the nearest ten to get 40.

We use≈to denoteapproximately equal to.$38 is between 30 and 40.

It is nearer to 40 than to 30.

$38 ≈ $40

Joyce bought the shoes for about $40.

Jarrel bought a cap for $22.

Weround down22 to the nearest ten to get 20.$22 is between 20 and 30.

It is nearer to 20 than to 30.

$22 ≈ $20

Jarrel bought the cap for about $20.

- Study the digit in the ones place.
- If it is equal to or more than 5, add 1 to the digit in the tens place (i.e. round up)
- If it is less than 5, keep the digit in the tens place unchanged (i.e. round down)

- Now, change the digit in the ones place to 0.

Rounding off to the nearest hundred

How many passengers can the aeroplane hold? How many passengers can the train hold? Round off your answers to the nearest hundred.

The aeroplane has 208 seats.

Weround down208 to the nearest hundred to get 200.208 is between 200 and 300.

It is nearer to 200 than to 300.

208 ≈ 200

The aeroplane can hold about 200 passengers.

The train has 1753 seats.

Weround up1753 to the nearest hundred to get 1800.1753 is between 1700 and 1800.

It is nearer to 1800 than to 1700.

1753 ≈ 1800

The train can hold about 1800 passengers.

- Study the digit in the tens place.
- If it is equal to or more than 5, add 1 to the digit in the hundreds place (i.e. round up)
- If it is less than 5, keep the digit in the hundreds place unchanged (i.e. round down)

- Now, change the digits in the tens and ones places to 0s.

Estimate the value of

- 412 + 37
- 2187 − 213
- 586 × 4
- 641 ÷ 7

a. 412 + 37412is410when rounded off to the nearest ten.

37is40when rounded off to the nearest ten.

≈ 410 + 40

= 450

b. 2187 − 2132187is2200when rounded off to the nearest hundred.

213is200when rounded off to the nearest hundred.

≈ 2200 − 200

= 2000

c. 586 × 4586is600when rounded off to nearest hundred.

≈ 600 × 4

= 2400

Think of multiples of 7.d. 651 ÷ 7

..., 56,63, 70, 77, ...

..., 560,630, 700, 770, ...

651 is nearer to 630 than to 700.

651 ÷ 7

≈ 630 ÷ 7

= 90