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1/4" + 3/8"

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

1/4" + 3/8" =

=0-5/8"

Sum

0-5/8"

Decimal inch

0.625"

Millimetres

15.875 mm

1/4" − 3/8"

-0-1/8"

The work

Over a common denominator

Put both over 8: 1/4 = 2/8 and 3/8 = 3/8. Add the tops: 2/8 + 3/8 = 5/8. Reduced, that's 0-5/8" (0.625 inches). TapeMath tracks it as an exact fraction, so it lands dead on the tape mark.

Keep going

1/4" to decimal 3/8" to decimal All fraction sums Add it on the calculator

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