1½ is called a "mixed number" because it's a combination of a Whole number (1) and a fraction (½).
We say 1½ outloud as "one and one-half" or "one and a half". Here, the word "and" really means "plus". We don't write + and we don't say "plus" but all mixed numbers are the sum of a Whole number and a fraction.
1½ means 1+½
All mixed numbers can be written in decimal form.
1½ = 1.5
Here, the decimal point means plus.
1.5 is 1+0.5
The fractional part of this mixed number (0.5) shows digit 5 in the tenths place.
0.5 = 5/10
5/10 reduces to 1/2
1½ = 1+½ = 1+0.5 = 1.5
Note: some fractions have a repeating decimal form.
1/3 = 0.3333… (the dots indicate digit 3 repeats forever)
4/7 = 0.57142857142857142857142857…
Another way to write a repeating decimal is to draw a bar over the repeating part.
\(\displaystyle \frac{1}{3} = 0.\overline{3}\\
\;\\
\frac{4}{7}= 0.57\overline{142857}\)
:cool: