Abirthday cake was measured with a degree of accuracy to the nearest 1cm; 10cm × 10cm × 5cm. what is the largest possible volume of the cake to the nearest cm3?

Since the cake was measured to the degree of accuracy to the nearest 1cm, the cake could either be larger or smaller than the dimensions given by 0.5cm.
So, the largest possible volume would be

(10+0.5)(10+0.5)(5+0.5)=606.375

Since it says to the nearest cm3, we round and get 606 cm3.

Hope this helps!