Question

Calculate 16.8 divided by 0.35 to the hundredths place without a calculator. Show your work.b. Describe the standard procedure for deter-mining where to put the decimal point in the answer to 16.8 , 0.35.c. Explain in two different ways why the place-ment of the decimal point that you described in part (b) is valid

Answer 1

a 48

b place value system

c

• it is valid because it helps in getting the correct answer
• it is valid because it helps in knowing the real position of the decimal point

Explanation:

use long division method

16.8 by 0.35

we move the decimal places to place to right

it becomes 1680 divided by 35

48

35 l 1680

- 140

280

- 280

0000

the standard procedure for deter-mining where to put the decimal point in the answer to 16.8 , 0.35 is the use of place value system

16.8 move the decimal point two places two places to the right that is 1680

and 0.35 move the decimal point two places to the right that is 35

• it is valid because it helps in getting the correct answer
• it is valid because it helps in knowing the real position of the decimal point

Answer 2

To calculate 16.8 ÷ 0.35 without a calculator, let's first move the decimal of both values 2 places to the right.

We now have 1680.00 ÷ 35.00

Therefore we have:

____48.00

35✓1680.00

___-140

_________

___280

___-280

________

____0

Let's now move 2 decimal places to the left.

Thus, 16.8÷0.35 = 48.00

b) The standard procedure:

You move the decimal places in both values 2 places to the right to make them whole numbers.

After dividing, the decimal place of the answer is then moved back 2 places to the left.

c) (i) Let's consider we multiply both values by 100.

`(16.8*100)/(0.35*100)`

`= (1680)/(35)`

= 1680÷35

We can see that the decimal we moved 2 places to the right is correct.

ii) We can express the values in dollars as $16.8÷ $0.35

We can also express in cents as (16.8*100) 1680 cents and (0.35*100) 35 cents.

Expressing as cents, the values become:

1680 ÷ 35.

Thus, moving the decimal two places to the right is correct