Adding and Subtracting Within 1,000: math test solutions, Grade 2 – download the PDF

1 Calculate / 4 pts

1. \(346 + 231 = 577\) (1 pt)
2. \(458 + 267 = 725\), regrouping ones and tens (1 pt)
3. \(672 - 341 = 331\) (1 pt)
4. \(703 - 258 = 445\), trading across the zero (1 pt)

2 Missing numbers / 3 pts

1. \(402 - 164 = 238\) (1 pt)
2. \(615 - 287 = 328\) (1 pt)
3. \(349 + 126 = 475\) (1 pt)

3 Base-ten drawing / 3 pts

1. \(7 + 6 = 13\) cubes. (1 pt)
2. 13 cubes make 1 rod and 3 cubes, so \(4 + 8 + 1 = 13\) rods. (1 pt)
3. 13 rods make 1 flat and 3 rods, and \(2 + 1 + 1 = 4\) flats. \(247 + 186 = 433\). (1 pt)

4 Estimate / 3 pts

1. \(500 + 300 = 800\) (1 pt)
2. \(600 - 400 = 200\) (1 pt)
3. \(497 + 305 = 802\), close to the estimate 800 (1 pt)

5 Bakery problem / 4 pts

1. \(234 + 187 = 421\) (1 pt)
2. \(421 + 96 = 517\) (1 pt)
3. \(600 - 517 = 83\) (1 pt)

Answer sentence: the bakery had 83 muffins left over. (1 pt)

6 Find the error / 3 pts

1. \(335 + 178 = 513\), which is not 503. (1 pt)
2. \(503 - 178 = 325\). Check: \(325 + 178 = 503\). (1 pt)
3. Jake traded a ten for the ones but forgot to lower the tens digit from 10 to 9, so he wrote \(10 - 7 = 3\) instead of \(9 - 7 = 2\). (1 pt)