Also, the NBT standard expects students to be able to explain why addition and subtraction strategies work using place value and properties of operations. Explanations can be supported by drawings and objects. This is an important skill for your child as students are expected to provide explanations for their answers in the classroom and on tests. We are working in second grade to set the foundation for your child to have the skills necessary to provide written explanations in third grade and beyond.
This week, we used place value disks on a place value chart to represent the composition of 10 ones as 1 ten with two-digit addends. The use of manipulatives reminds students that they must add like units (e.g., 26 + 35 is 2 tens + 3 tens and 6 ones + 5 ones). As students work with the place value disks they make a ten out of ten ones and then exchange them for one 10. We record each step on the vertical problem to help them to learn the algorithm.
While some students may already know the algorithm for adding bigger numbers including regrouping, the process of connecting their understanding to the concrete and pictorial representations develops meaning and understanding of why the process works, not just how to use it.
Next week, students will bring home a set of place value disks to cut out and use at home. By using place value disks on a place value chart students will gain deeper understanding of the process. As a result, they will be better able to systematically model the standard addition algorithm including the composition of a ten.
In our language arts lessons we practiced citing evidence from the text. We read that elephant seals have many ways to survive in the sea and on land in their icy home. Students were asked to refer back to the text and state ways that the elephant seals survive in Antarctica with its freezing cold winds and icy water. Ask your child to name some of the ways the elephant seals are able to survive in their natural habitat.
The Nordstrom Spelling Bee happens this Thursday, January 15. Students will receive a second list of words to study next week. We do not know which words will be chosen for the Spelling Bee test, so students should learn to spell at least 15 new words from the official list to help them "Bee" their best on the test.