Adding Subtracting Mentally

Match the following:

• 405

• 278 + 100

• 120

• 277 + 10

• 299

• 395 + 10

• 378

• 199 + 100

• 287

• 5 tens + 7 tens

Tags

CCSS.2.NBT.B.8

555 + 10

Tags

CCSS.1.NBT.C.5

676 - 10

Tags

CCSS.1.NBT.C.5

843 + 100

Tags

CCSS.2.NBT.B.7

234 - 100

Tags

CCSS.2.NBT.B.8

555 + 10 + 100

Tags

CCSS.2.NBT.B.8

999 -10 -100

Tags

CCSS.2.NBT.B.8

Mentally adding/subtracting 10s and 100s is

• Super Easy

• Easy

• Somewhat Hard

• Very Hard

Tags

CCSS.2.NBT.B.8

2000 + 100 + 10

Tags

CCSS.4.NBT.A.2

True or False: The commutative property of addition states that changing the order of the numbers being added does not change the sum.

• True

• The commutative property of addition only applies to odd numbers

• The commutative property of addition only applies to even numbers

• False

Tags

CCSS.1.OA.B.3