Answer: 1 and 21/100
Step-by-step explanation: Using the place value chart, we can see that 1.21 means 1 unit, 2 tenths, and 1 hundredth.
Think of 2 tenths and 1 hundredth as 21 hundredths.
So we have 1 and 21/100 which can
be written as the mixed number [tex]1\frac{21}{100}[/tex].
I have attached the place value chart below.