Convert the mixed number
to an improper fraction.
Understand what the mixed number means. A mixed number is a sum in disguise:
An improper fraction writes that whole sum over the single denominator , so the job is to convert the wholes into eighths and add on the eighths you already have.
Multiply the whole number by the denominator. Each whole equals , i.e. eighths, so wholes are
eighths in total. This is the step the shortcut “multiply, add, keep the bottom” compresses.
Add the numerator. Now include the extra :
so there are eighths altogether.
Keep the original denominator. The size of each piece never changed — only how many you are counting — so the denominator stays :
Combining as fractions gives the same thing: .
Sanity-check the size and the form. With a two-digit whole number the multiplication is the only real work: . A quick estimate guards against slips — the answer must be a little over , and is.
Reverse the process to confirm. Dividing back, remainder , which rebuilds exactly. As a decimal both forms equal , so the conversion is verified in both directions.
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