Question

What is `0.9978+0.325`?

Answer 1

`1.3228`

Explanation:

When adding decimals it is very important to line up the decimal point and place numbers of the same value..

`color(white)(xxxxxx)0.9978`
`color(white)(xxxx)+ul0.325`
`color(white)(xxxx)= 1.3228`

If there is no digit shown - treat it as 0.

When you add,you now add the digits with the same place value together.

so 9/10 must be above 3/10 and
9/100 must be above 2/100 and
7/1000 must be above 5/1000
8/10000 is alone.

Answer 2

`1.3228`

Explanation:

write as:

`color(brown)("counting column from the right")`

`0.9978`
`ul(0.3250) larr" notice the place holder of 0 at the end of 0.325"`
`ul(color(white)(0.3250))`
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
`color(blue)("Adding column 1")`

`0.9color(white)(.)9color(white)(.)7color(white)(.)color(red)(8)`
`ul(0.3color(white)(.)2color(white)(.)5color(white)(.)color(red)(0))`
`ul(color(white)(0.3.2.5.0)color(green)(8)) larr" 8 + 0 = 8 nothing to carry"`

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
`color(blue)("Adding column 2")`

`0.9color(white)(.)9color(white)(..)color(red)(7)color(white)(.)8`
`ul(0.3color(white)(.)2color(white)(..)color(red)(5)color(white)(.)0)`
`color(white)(.)ul(color(white)(0.3.2.)color(green)(2)color(white)(.)8) larr" 7+5=12 giving " color(green)(2 )" and "color(magenta)(1)" to carry"`
`color(white)(......)color(magenta)(1)`

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
`color(blue)("Adding column 3")`

`0.9color(white)(.)color(red)(9)color(white)(.)7color(white)(.)8`
`ul(0.3color(white)(.)color(red)(2)color(white)(.)5color(white)(.)0)`
`ul(color(white)(0.3)color(white)(.)color(green)(2)color(white)(.)2color(white)(.)8) larr" 9+2+1 =12 giving " color(green)(2 )" and "color(magenta)(1)" to carry"`
`color(white)(..)color(magenta)(1)color(white)(.)1`

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
`color(blue)("Adding column 4")`

`"0."color(white)(.)color(red)(9)color(white)(.)9color(white)(.)7color(white)(.)8`
`ul("0."color(white)(.)color(red)(3)color(white)(.)2color(white)(.)5color(white)(.)0)`
`ul("0."color(white)(.)color(green)(3)color(white)(.)2color(white)(.)2color(white)(.)8) larr" 9+3+1 =13 giving " color(green)(3 )" and "color(magenta)(1)" to carry"`
`color(white)()color(magenta)(1)color(white)(.)1color(white)(.)1`

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
`color(blue)("Adding column 5")`

`color(red)("0.")color(white)(.)9color(white)(.)9color(white)(.)7color(white)(.)8`
`ul(color(red)("0.")color(white)(.)3color(white)(.)2color(white)(.)5color(white)(.)0)`
`ul(color(green)("1.")color(white)(.)3color(white)(.)2color(white)(.)2color(white)(.)8) larr" 0+0+1 =1 giving " color(green)(1 )" and "color(magenta)(0)" to carry"`
`color(white)()1color(white)(.)1color(white)(.)1`