Add whole numbers. Find the sum. 1,282 + 281 = 1,563

1b. 3,879 + 1,082

$$\text { Find } \frac{1}{8} \text { of } \$ 54.80 \text {. }$$

Find the markup and the rate of markup based on cost.

$$\begin{array}{|l|l|r|r|l|l|} \hline & {\begin{array}{c} \text { Stock } \\ \text { Number } \end{array}} & {\text { Cost }} & \begin{array}{c} \text { Selling } \\ \text { Price } \end{array} & \text { Markup } & \begin{array}{c} \text { Rate of } \\ \text { Markup } \\ \text { On Cost } \end{array} \\ \hline \text { 18. } & 501-\mathrm{A} & \$ 77.25 & \$ 101.97 & & \\ \hline \text { 19. } & 501-\mathrm{B} & 150.00 & 225.00 & & \\ \hline \text { 20. } & 503-\mathrm{AA} & 720.00 & 864.00 & & \\ \hline 21 . & 556-\mathrm{M} & 110.25 & 147.00 & & \\ \hline 22 . & 576-\mathrm{V} & 42.00 & 60.90 & & \\ \hline \end{array}$$