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13/16" + 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.

13/16" + 7/8" =

=1-11/16"

Sum

1-11/16"

Decimal inch

1.6875"

Millimetres

42.8625 mm

13/16" − 7/8"

-0-1/16"

The work

Over a common denominator

Put both over 16: 13/16 = 13/16 and 7/8 = 14/16. Add the tops: 13/16 + 14/16 = 27/16, which carries past one inch. Reduced, that's 1-11/16" (1.6875 inches). TapeMath tracks it as an exact fraction, so it lands dead on the tape mark.

Keep going

13/16" to decimal 7/8" to decimal All fraction sums Add it on the calculator

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