Question

The coastline of the United States is 12,383 miles long. Canada's coastline is 113,211 miles longer than the coastline of the United States. How long is the coastline of Canada?

Answer 1

Canadaá coast line is `125594" miles"`

Explanation:

The coastline of the United States is 12,383 miles long.

As Canada's coastline is 113,211 miles longer than the coastline of the United States,

the coastline of Canada must be

`color(white)(x.)1color(white)(.)2color(white)(.)3color(white)(.)8color(white)(.)3`

`ul(+color(white)(.)1color(white)(.)1color(white)(.)3color(white)(.)2color(white)(.)1color(white)(.)1)`

`ul(color(white)(xx)1color(white)(.)2color(white)(.)5color(white)(.)5color(white)(.)9color(white)(.)4" miles")`

Observe that starting from units, tens, hundreds and so on up to hundred thousands, there is no carry and hence easy to add.