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3/8" + 7/16"

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

3/8" + 7/16" =

=0-13/16"

Sum

0-13/16"

Decimal inch

0.8125"

Millimetres

20.6375 mm

3/8" − 7/16"

-0-1/16"

The work

Over a common denominator

Put both over 16: 3/8 = 6/16 and 7/16 = 7/16. Add the tops: 6/16 + 7/16 = 13/16. Reduced, that's 0-13/16" (0.8125 inches). TapeMath tracks it as an exact fraction, so it lands dead on the tape mark.

Keep going

3/8" to decimal 7/16" to decimal All fraction sums Add it on the calculator

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