Decimal fractions are fractions whose denominators are a
power of 10.
Decimal fractions can be converted to decimal numbers using place value.

The model is one whole divided into ten equal parts with nine parts shaded.
So, the model shows nine tenths.
Nine tenths written as a decimal has a 9 in the tenths place.
So, written as a decimal is 0.9.
The model is one full whole and one whole divided into one hundred equal parts with twenty-six parts shaded.
So, the model shows one and twenty-six hundredths.
One and twenty-six hundredths written as a decimal has a 1 in the ones place, a 2 in the tenths place, and a 6 in the hundredths place.
So, written as a decimal is 1.26.