Mrs. Boyd is aware that her first-grade students are very concrete thinkers. She works hard to make sure that she is using her understanding of their development as she prepares her lesson.

Which of the following would be useful for her to include in her math lesson on addition?

a) Take a formative assessment first.

b) Using manipulatives to solve the addition problems.

c) Practice addition problems with paper and pencil.

d) Talk about how to solve addition problems in partners.