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3/8" + 1/2"

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" + 1/2" =

=0-7/8"

Sum

0-7/8"

Decimal inch

0.875"

Millimetres

22.225 mm

3/8" − 1/2"

-0-1/8"

The work

Over a common denominator

Put both over 8: 3/8 = 3/8 and 1/2 = 4/8. Add the tops: 3/8 + 4/8 = 7/8. Reduced, that's 0-7/8" (0.875 inches). TapeMath tracks it as an exact fraction, so it lands dead on the tape mark.

Keep going

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