Add and subtract within 20 on an open number line

Add and subtract within 20 on an open number line

In this lesson you will learn how to add and subtract within 20 using an open number line.

ADDITIONAL MATERIALS

STANDARDS

CCSS.2.OA.B.2 Fluently add and subtract within 20 using mental strategies. By end of Grade 2, know from memory all sums of two one-digit numbers. See standard 1.OA.6 for a list of mental strategies.

TEKS.2.4.A recall basic facts to add and subtract within 20 with automaticity;

TEKS.1.3.D apply basic fact strategies to add and subtract within 20, including making 10 and decomposing a number leading to a 10;

VA.CE.2.6.b determine sums and differences, using various methods; and

VA.CE.2.5.b demonstrate fluency with addition and subtraction within 20.

FL.MAFS.2.OA.2.2 Fluently add and subtract within 20 using mental strategies. By end of Grade 2, know from memory all sums of two one-digit numbers.