standard_description: Apply properties of operations as strategies to add and subtract. (Students need not use formal terms for these properties.) Examples: If 8 + 3 = 11 is known, then 3 + 8 = 11 is also known. (Commutative property of addition.) To add 2 + 6 + 4, the second two numbers can be added to make a ten, so 2 + 6 + 4 = 2 + 10 = 12. (Associative property of addition.)
problem_activity: Task
Dennis and Cody are building a castle out of plastic building blocks. They will need $2\frac12$ buckets of blocks for the castle they have in mind. Dennis used to have two full buckets of blocks but lost some and now has $1\frac34$ buckets. Cody used to have two full buckets of blocks too, but now has $1\frac14$ buckets. If Dennis and Cody combine their buckets of blocks, will they have enough to build their castle?


aligns: no