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    <p>What you are observing is the result of <strong>integer truncation</strong>. When doing integer division with two integer operands, the result will be another integer, with the <em>fractional</em> part thrown away. Note that this is different from rounding, e.g, with truncation 3.8 will become 3.</p> <p>This will give you your expected output:</p> <pre><code>double sum = ((117+130) / 3.0) + ((130+13) / 3.0); </code></pre> <p>since we divide by <code>3.0</code> rather than <code>3</code>.</p> <p>I.e., if at least <em>one</em>, or <em>both</em> of the operands in an integer division is a float type, the result will be a float. (Note that I'm using float/double here somewhat interchangeably with regard to <code>int</code>s and truncations)</p> <p>In addition to appending a <code>.</code> or <code>.0</code> to values (<code>.0</code> will generate a <code>double</code>, while <code>.0f</code> will generate a <code>float</code> - as pointed out by @Morwenn's helpful comment below), we can also explicitly cast ints to floats, but it matters <em>when</em> we do it. A simple example (note that the values end up as <code>float</code> <em>after</em> the assignment in this example in any case since <code>v</code> is a <code>float</code>):</p> <pre><code>float v = 0; /* values shown are BEFORE assignment */ v = (5 / 2); /* value is 2 due to integer truncation before assignment */ v = (float) (5 / 2); /* 2.0 as integer division occurs 1st, then cast to float */ v = (float) 5 / 2; /* 2.5 since 5 becomes 5.0 through casting first. */ </code></pre> <p>I borrowed the above example from <a href="https://stackoverflow.com/a/11060283/1209279">Division and floating points</a></p>
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    1. COJust a small detail, but `.0` will generate a `double` while `.0f` will generate a `float`.
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    2. CO@Morwenn .. that's a good point. I guess I was speaking in more general terms where I meant to include both doubles/floats, but I'll make a note just to be sure and not cause any confusion for anyone down the line. Thanks.
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    3. COThanks folks, very helpful!
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