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1/2" + 7/8"

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

1/2" + 7/8" =

=1-3/8"

Sum

1-3/8"

Decimal inch

1.375"

Millimetres

34.925 mm

1/2" − 7/8"

-0-3/8"

The work

Over a common denominator

Put both over 8: 1/2 = 4/8 and 7/8 = 7/8. Add the tops: 4/8 + 7/8 = 11/8, which carries past one inch. Reduced, that's 1-3/8" (1.375 inches). TapeMath tracks it as an exact fraction, so it lands dead on the tape mark.

Keep going

1/2" to decimal 7/8" to decimal All fraction sums Add it on the calculator

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