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1/8" + 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.

1/8" + 7/8" =

=1"

Sum

Decimal inch

Millimetres

25.4 mm

1/8" − 7/8"

-0-3/4"

The work

Over a common denominator

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

Keep going

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

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