Mental Math Addition and Estimating

Solve 12+10

Tags

CCSS.1.OA.A.1

Solve 15+10

Tags

CCSS.1.OA.A.1

Solve 40+56

Tags

CCSS.2.NBT.B.5

Solve 24+61

Tags

CCSS.1.NBT.C.4

CCSS.2.NBT.B.5

Find the BEST estimate of 175 + 426 and then add.

• Estimate : 100 + 400= x

  100 + 400 = 500

  x = 500

• Estimate : 180 + 430= x

  80 + 30 = 110

  100 + 400 + 500

  110 + 500 = 610

  x = 610

• Estimate : 175 + 425 = x

  75 + 25 = 100

  100+ 400 = 500

  100 + 500 = 600

  x = 600

Tags

CCSS.3.NBT.A.1

CCSS.3.NBT.A.2

CCSS.3.OA.D.8

Since we know that 175 + 425 = 600 from doing fast mental math, what is the exact answer of 175 + 426?

Tags

CCSS.2.NBT.B.7

CCSS.3.NBT.A.2

Doug collected caterpillars. He found 238 on Monday and 546 on Tuesday. About how many caterpillars did Doug find?

• About 346 caterpillars

• About 790 caterpillars

• About 890 caterpillars

• About 900 caterpillars

Tags

CCSS.1.NBT.C.4