Warm up with a Mystery Math Mistake to add 9 and 5 using a double 10-frame and a decompose strategy. Use near-doubles to add with double 10-frames and a compensation strategy.

Warm up with a Mystery Math Mistake to find the mistake made in counting up on a number line to subtract. Use visual models to practice adding and subtracting lengths of objects within 100.

Warm up with a Mystery Math Mistake to hunt for the mistake made counting up on the number line. Use a Rekenrek and number line to explore rounding numbers to the nearest ten and hundred.