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1/8" + 5/16"

Adding two fractions of an inch, exactly — the everyday jobsite arithmetic that a decimal calculator gets wrong. Reduced, carried, and shown in millimetres.

1/8" + 5/16" =

=0-7/16"

Sum

0-7/16"

Decimal inch

0.4375"

Millimetres

11.1125 mm

1/8" − 5/16"

-0-3/16"

The work

Over a common denominator

Put both over 16: 1/8 = 2/16 and 5/16 = 5/16. Add the tops: 2/16 + 5/16 = 7/16. Reduced, that's 0-7/16" (0.4375 inches). TapeMath tracks it as an exact fraction, so it lands dead on the tape mark.

Keep going

1/8" to decimal 5/16" to decimal All fraction sums Add it on the calculator

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