mental arithmetic

680 + 20

• 670

• 700

• 720

320 - 35

• 300

• 250

• 285

18 + 2 +5

• 30

• 25

• 28

10 - 3 + 40

• 47

• 37

• 27

30 + 30 - 7

• 67

• 35

• 53

find the pattern number in the sequence.

120, 140, 160

• + 20

• +10

• +15

find the pattern number in the sequence.

536, 436, 336

• + 100

• +6

• -100

find the pattern number in the sequence.

55, 60, 65

• + 10

• +5

• -15

find the pattern number in the sequence.

79, 76, 73

• + 3

• - 7

• -3

250 - 50 + 10

• 210

• 300

• 120