Math Intervention 3–5 Grade

62 Addition and Subtraction Concepts

What is the Adding and Subtracting Tens

Concept?

Adding and subtracting tens builds fl uency with number

relationships and computation. When students understand

the adding and subtracting tens concept, they are more apt

to use mental math to solve problems and verify answers.

Initially, students add and subtract tens to and from multiples

of ten. Building on this idea, they learn to add and subtract

tens to and from any number.

CCSS

Operations and Algebraic Thinking

Number and Operations in Base Ten

Formative Assessment

To fi nd out if a student can add and subtract tens, ask the

student to solve the following equations:

20 + 10 =

40 – 10 =

50 + 30 =

70 – 20 =

65 + 10 =

82 – 10 =

38 + 40 =

97 – 30 =

Ask the student to explain how he solved each problem.

Analyze the student’s profi ciency through his accuracy,

speed, and explanations.

Adding and Subtracting Tens

CONCEPT: