need to help my husband with his math?

Question

would someone please show me how do i do these problems and show the work?
divide the following numbers to the nearest hundreth:
1. 6.45 / 10 =
2. 0.13 / 0.25 =

round the following decimals to the nearest thousand:
1. 0.5673
2. 7.8393

Answer 1

Dividing by 10 is the opposite of multiplying by 10. Move the decimal place to the left:

1. 6.45 / 10 = 0.645, or 0.65 { to the nearest hundreth }

When you divide by a fraction, it's the same as multiplying by the fraction's reciprocal:

2. 0.13 / 0.25 = 0.13 * 4 { 0.25 = 1/4 }
0.13 * 4 = 0.52

Rounding to the nearest thousanth is to leave the answer with only three decimal places to the right of the decimal point, and adjusting the last digit based on the fourth decimal place:

1. 0.5673 = 0.567 { rounded down because the next digit is 3 }
2. 7.8393 = 7.839 { rounded down because the next digit is 3 }

If the next digit was 5 or greater, then you would round up to the next thousanth.

e.g. 7.8397 = 7.840 { rounded up }

Answer 2

1. 6.45 / 10=?

Here's how I do it: 6.45/10=(6/10)+(0.45/10)

6/10=0.6 (just move the decimal place along one, or two if dividing by 100, 3 for 1000 etc.)

0.45/10=0.045
0.6+0.045=0.645

2. 0.13/0.25=?

If you multiply both numbers in a fraction (top and bottom) by the same number, then the fraction stays the same value eg.

0.13/0.25=13/25 (I multiplied both by ten)
13/25=26/50 (multiplied by 2)
26/50=52/100 (multiplied by 2 again)

so you could just say 0.13/0.25=52/100

and by moving the decimal place by two....

52/100=0.52

to the nearest hundredth means to the second decimal place or the "2" in 0.52 as 52/100 is equal to 52 hundredths.

rounding to the nearest thousand is as easy as deciding on the "thousands" column and deciding if its above or below 5

fo 0.5673, the 7 is the thousandths column - three places along from the decimal place. 3 is below 5, so number is rounded to
0.567

as for 7.8393, the 9 is in the thousandths column and so rounding the final 3 down (as its also below 5) gives

7.839

hope that helps, i'm not sure that there is any working to show for the second 2 questions though

Answer 3

Whenever you divide by 10 simply move the decimal point one place to the left.

Decimals in both the numerator and denominator may be converted to whole numbers by multiplying by power of 10.
For example .13/.25 = 13/25 or .427/.67 = 42.7/67 or .534/.132 = 534/132

Finally, to round to the nearest thousand (that's the third decimal place we would have .567 and 7.839. Had the first number been .5676 it would have rounded to .568

Hope this helps a little. A good arithmetic book should explain a lot of this kind of work. Good luck with it.

Answer 4

6.45 / 10=0.645 then round it it will = 0.600

0.13 / 0.25= 0.52 then round it it will = 0.53


0.5673=0
7.8393=0