Estimation

This array =....×.....

• 5×5

• 6×5

• 2×3

250=245

• Rounding to 10

• Rounding to 100

• Rounding to 1

256=200

• Rounding to 10

• Rounding to 1

• Front end estimation

This array=...×....

• 3×3

• 4×3

• 2×3

436=.......by rounding to the nearest 10

• 430

• 400

• 440

195=.....by front end estimation strategy

• 200

• 100

• 190

This array=....+....+....+....+....

• 4+4+4+4+4

• 5+5+5+5+5

• 2+2+2+2+2

This array=...×....

• 3×3

• 4×3

• 2×3

26,30,34,....,42

• 38

• 40

• 32

28,26,24,22,20,18 The pattern rule is......

• +4

• -2

• +2