Add and subtract single and double-digit numbers with and without regrouping, to include problems with money.
2.2.2.A Develop fluency in the use of basic facts for addition and subtraction
2.2.2.D Estimate values, sums, and differences of quantities and conclude the reasonableness of those estimates.
CC.2.1.2.B.3 Use place value understanding and properties of operations to add and subtract within 1000.
CC.2.2.2.A.2 Use mental strategies to add and subtract within 20.