Given: 7.351
Just for demonstration I am going to insert the part of the number we are interested in inside square brackets.
Write 7.351" as "[color(white)(2/2)7.3]51
The number immediately to the right of the closing bracket is 5.
The general rule is:
color(brown)("If the trailing number ( my choice of wording) is 5 or more then we")
color(brown)("round up. If the 'trailing number' is less than 5 we round down.")
color(brown)("By 'rounding down' they mean that the number part inside the")
color(brown)("brackets is left as it is and the number part outside is discarded")
" "5>=5" so round up"
" "bar(ul(|color(white)(2/2) "So "7.351 =7.4" to 1 decimal place"color(white)(2/2|))| )
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Just to make the process clearer
Suppose we had [color(white)(2/2)7.3]21
2<5 so we round down giving 7.3
Suppose we had [color(white)(2/2)7.3]61
6>5 so we round up giving 7.4
