Number Combinations to 20 Checkpoint

How many beads do you see in the abacus (a)? Write two different equations to show how you know.

• Beads: 10 Equations: 5 + 5 = 10 and 10 = 5 + 5

• Beads: 8 Equations: 4 + 4 = 8 and 8 = 4 + 4

• Beads: 12 Equations: 6 + 6 = 12 and 12 = 6 + 6

• Beads: 9 Equations: 4 + 5 = 9 and 9 = 4 + 5

Tags

CCSS.2.OA.A.1

How many beads do you see in the abacus (b)? Write two different equations to show how you know.

• Beads: 13 Equations: 10 + 3 = 13 and 13 = 10 + 3

• Beads: 12 Equations: 6 + 6 = 12 and 12 = 7 + 5

• Beads: 15 Equations: 8 + 7 = 15 and 15 = 10 + 5

• Beads: 11 Equations: 5 + 6 = 11 and 11 = 9 + 2

Tags

CCSS.2.OA.A.1

Find each sum. 3 + 7 = ______

Tags

CCSS.1.OA.C.6

CCSS.2.OA.B.2

Find each sum. 6 + 4 = ______

Tags

CCSS.1.OA.A.1

Find each sum. 9 + 2 = ______

• 11

• 10

• 12

• 13

Tags

CCSS.1.OA.A.1

Find each sum. 9 + 10 = ______

• 19

• 18

• 21

• 20

Tags

CCSS.1.OA.A.1

Find each sum. 10 + 8 = ______

• 18

• 12

• 20

• 15

Tags

CCSS.1.OA.A.1

Find each difference. 10 - 6 = _______

• 4

• 2

• 5

• 6

Tags

CCSS.2.OA.A.1

Find each difference. 12 - 10 = _______

• 2

• 1

• 3

• 5

Tags

CCSS.2.OA.A.1

Find each difference. 14 - 4 = _______

• 10

• 8

• 12

• 6

Tags

CCSS.2.OA.A.1