So why are my age deductions so small?

Turbo Tax says my Federal Age Tax deduction is $1,680.80, and the Ontario deduction is $86.74. However, when I use the worksheets, downloaded from Revenue Canada, I get $5,138.83 Federally and $2,959.68. I moved into Canada in April and lived in the country 266 days or 72.77% of the year. So even on a pro rated basis for partial year residency, my numbers suggest that I should be getting $3,739.53 Federal and $2,153.76 Provincial. When this figures are used, my Federal Tax Income Tax is reduced by $308.81. And my Ontario Income Tax is reduced by $2,067.02. So why are these deductions so different?