Caitlin was measuring how much she and her brother Bill grew over two years.
In the first year Caitlin grew $6.5$6.5 cm and Bill grew $3.5$3.5 cm. In the second year Caitlin grew $4.4$4.4 cm and Bill grew $7.4$7.4 cm.
How much did Bill grow over the two years?
Understand operations on fractions, decimals, percentages, and integers