Find the sum.
23 + 9
Find the sum.
919 + 1,884
Find the sum.
49a + 27a
Find the sum.
18 + 62 + 121
Find the sum.
503a + 17a + 407a
Challenge! Brett has 324 basketball cards. His sister, Whonda, has 1,232 basketball cards. How many cards do they have altogether?