Warm up with a Mystery Math Mistake to compare expressions. Make a 10 to help you add. Use a double 10-frame and the "make 10" strategy to add two single-digit numbers.

Warm up with a Mystery Math Mistake to add 2 two-digit numbers. Explore how many inches there are in a foot. Practice picking the best unit, inches or feet, to measure the length of objects.

Warm up with a Mystery Math Mistake to find a mistake made in using an algorithm for addition and subtraction. Subtract within 1000 using strategies and algorithms based on place value, properties of operations, and/or the relationship between addition and subtraction.