Mental Math Set 2

Mental Math # 1 7.7  100 = 40 x 300 = 500 + 30 + 6000 + 2 = 6 + 8 = 156 + 8 = 200 + 400 + 53 = 3 x 10 + 6 x 1000 + 2 x 1 = 46.45 rounded to the nearest tenth = Five hundred and four thousandths = Which is larger 98.9 or 98.199 =

Mental Math # 1 7.7  100 = 0.077 40 x 300 = 12 000 500 + 30 + 6000 + 2 = 6532 6 + 8 = 14 156 + 8 = 164 200 + 400 + 53 = 653 3 x 10 + 6 x 1000 + 2 x 1 = 6032 46.45 rounded to the nearest tenth = 46.5 Five hundred and four thousandths = 500.004 Which is larger 98.9 or 98.199 = 98.9

Mental Math # 2 822.4  100 = 50 x 30 = 5 + 800 + 60 + 2000 = 7 + 5 = 335 + 7 = 2 x $3.99= 3 x 100 + 6 x 10 + 2 x 1000 = 8.4488 rounded to the nearest hundredth = ten and thirteen thousandths = =

Mental Math # 2 822.4  100 = 8.224 50 x 30 = 1500 5 + 800 + 60 + 2000 = 2865 7 + 5 = 12 335 + 7 = 342 2 x $3.99= $7.98 3 x 100 + 6 x 10 + 2 x 1000 = 2360 8.4488 rounded to the nearest hundredth = 8.45 ten and thirteen thousandths = 10.013 = 1.04 1

Mental Math # 3 105 cm = ____ m 2 L = _____ mL 5000 m = _____ km 3.4 mm = _____ cm 90 mL = _____ L 600 g = _____ kg 1 mg = _____ g 3 km = _____ m 0.01 g = _____ mg 20 m = _____ cm

Mental Math # 3 105 cm = 1.05 m 2 L = 2000 mL 5000 m = 5 km 3.4 mm = 0.34 cm 90 mL = 0.09 L 600 g = 0.6 kg 1 mg = 0.001 g 3 km = 3000 m 0.01 g = 10 mg 20 m = 2000 cm

Mental Math # 4 6 L = _____ mL 3700 m = _____km and _____m 59 km = _____ m 3.4 cm = _____mm 345 mL = _____L 69 mg = _____ g 1112 g = _____kg 9 km = _____ m 0.08 g = _____ mg 2160 m = _____ km and _____m

Mental Math # 4 6 L = 6000 mL 3700 m = 3 km and 700 m 59 km = 59 000 m 3.4 cm = 34 mm 345 mL = 0.345 L 69 mg = 0.069 g 1112 g = 1.112 kg 9 km = 9000 m 0.08 g = 80 mg 2160 m = 2 km and 160 m

Mental Math # 5 3900 mm = _____ m 4321 m = _____ km and _____ m 5900 mL = _____ L and _____ mL 47 cm = _____ mm 805 mL = _____ L 6 g = _____ mg 4 kg = _____ g 9 km = _____ hm 8 g = _____ dg 2002 m = _____ km and _____ m

Mental Math # 5 3900 mm = 3.9 m 4321 m = 4 km and 321 m 5900 mL = 5 L and 900 mL 47 cm = 470 mm 805 mL = 0.805 L 6 g = 6000 mg 4 kg = 4000 g 9 km = 90 hm 8 g = 80 dg 2002 m = 2 km and 2 m

Mental Math # 6 Have $10, spend $1.25 = Have $10, spend $3.45 =

Mental Math # 6 Have$10, spend $1.25 = $8.75

Mental Math # 7 Have $10, spend $2.75 = Have $10, spend $3.55 =

Mental Math # 7 Have $10, spend $2.75 = $7.25

Mental Math # 8 Have $10, spend $2.80 = Have $10, spend $5.35 =

Mental Math # 8 Have $10, spend $2.80 = $7.20

Mental Math # 9 Have $10, spend $3.35 = Have $10, spend $7.40 =

Mental Math # 9 Have $10, spend $3.35 = $6.65

Mental Math # 10 Have $10, spend $8.30 = Have $10, spend $1.41 = $3.99 + ? = $10.00 5.2 + ? = 10 Have $20, spend $11.50 = Have $20, spend $7.68 = 0.74 + ? = 5 ? + 4.085 = 5 17.10 + ? = 20

Mental Math # 10 Have $10, spend $8.30 = $1.70 $3.99 + $6.01 = $10.00 5.2 + 4.8 = 10 Have $20, spend $11.50 = $8.50 Have $20, spend $7.68 = $12.32 0.74 + 4.26 = 5 0.915 + 4.085 = 5 17.1 + 2.9 = 20

Mental Math # 11 Have $10, spend $5.15 = Have $10, spend $3.57 = $4.61 + ? = $10.00 3.7 + ? = 10 Have $20, spend $12.75 = Have $20, spend $9.50 = 0.31 + ? = 1 ? + 2.425 = 5 15.5 + ? = 20

Mental Math # 11 Have $10, spend $5.15 = $4.85 $4.61 + $5.39 = $10.00 3.7 + 6.3 = 10 Have $20, spend $12.75 = $7.25 Have $20, spend $9.50 = $10.50 0.31 + 0.69 = 1 2.575 + 2.425 = 5 15.5 + 4.5 = 20

Mental Math # 12 20 + 14 = 55 + 43 = 38 + 26 = 65 + 27 = 78 + 135 = 23 + 59 = 48 + 24 = 45 + 48 = 36 + 47 = 263 + 43 =

Mental Math # 12 20 + 14 = 34 55 + 43 = 98 38 + 26 = 64 65 + 27 = 92 78 + 135 = 213 23 + 59 = 82 48 + 24 = 72 45 + 48 = 93 36 + 47 = 83 263 + 43 = 306

Mental Math # 13 46 + 27 = 35 + 48 = 18 + 73 = 94 + 26 = 82 + 225 = 77 + 19 = 49 + 49 = 23 + 45 = 32 + 41 + 60 = 227 + 63 =

Mental Math # 13 46 + 27 = 73 35 + 48 = 83 18 + 73 = 91 94 + 26 = 120 82 + 225 = 307 77 + 19 = 96 49 + 49 = 98 23 + 45 = 68 32 + 41 + 60 = 133 227 + 63 = 290

Mental Math # 14 30 + 25 + 70 = 35 + 40 + 60 + 20 = 50 + 95 + 50 = 10 + 75 + 50 + 50 + 25 = 90 + 25 + 75 + 10 = 85 + 25 + 25 + 15 = 20 + 80 + 55 + 30 + 45 = 35 + 20 + 90 + 65 = 20 + 40 + 60 + 180 = 300 + 700 + 600 =

Mental Math # 14 30 + 25 + 70 = 125 35 + 40 + 60 + 20 = 155 50 + 95 + 50 = 195 10 + 75 + 50 + 50 + 25 = 210 90 + 25 + 75 + 10 = 200 85 + 25 + 25 + 15 = 150 20 + 80 + 55 + 30 + 45 = 230 35 + 20 + 90 + 65 = 210 20 + 40 + 60 + 180 = 300 300 + 700 + 600 = 1600

Mental Math # 15 50 + 25 + 75 = 35 + 70 + 30 + 65 + 10= 20 + 50 + 150 = 70 + 10 + 30 + 60 + 40 = 90 + 55 + 45 + 10 + 80 = 25 + 25 + 25 + 50 = 20 + 80 + 55 + 30 + 45 = 100 + 200 + 900 + 65 = 200 + 50 + 130 + 50 = 200 + 70 + 800 + 30 =

Mental Math # 15 50 + 25 + 75 = 150 35 + 70 + 30 + 65 + 10= 210 20 + 50 + 150 = 220 70 + 10 + 30 + 60 + 40 = 210 90 + 55 + 45 + 10 + 80 = 280 25 + 25 + 25 + 50 = 125 20 + 80 + 55 + 30 + 45 = 230 100 + 200 + 900 + 65 = 1265 200 + 50 + 130 + 50 = 430 200 + 70 + 800 + 30 = 1100

Mental Math # 16 29 + 75 = 56 + 52= 25 + 54 = 175 + 24 = 90 + 55 = 26 + 99 = 98 + 79 = 125 + 77 = 258 + 50 = 215 + 90 =

Mental Math # 16 29 + 75 = 104 56 + 52= 108 25 + 54 = 79 175 + 24 = 199 90 + 55 = 145 26 + 99 = 125 98 + 79 = 177 125 + 77 = 202 258 + 50 = 308 215 + 90 = 305

Mental Math # 17 28 + 75 = 225 + 76 = 25 + 98 = 198 + 28 = 390 + 38 = 87 + 198 = 99 + 209 = 175 + 27 = 325 + 79 = 50 + 158 =

Mental Math # 17 28 + 75 = 103 225 + 76 = 301 25 + 98 = 123 198 + 28 = 226 390 + 38 = 428 87 + 198 = 285 99 + 209 = 308 175 + 27 = 202 325 + 79 = 404 50 + 158 = 208

Mental Math # 18 2 x 75 x 5 = 2 x 7 x 5 x 5 x 2 = 25 x 9 x 4 =

Mental Math # 18 2 x 75 x 5 = 750 2 x 7 x 5 x 5 x 2 = 700 25 x 9 x 4 = 900 10 x 16 x 2 = 320 5 x 20 x 38 = 380 8 x 4 x 5 = 160 97 x 2 x 5 = 970 500 x 33 x 2 = 33 000 25 x 2 x 40 = 2000 50 x 56 x 2 = 5600

Mental Math # 19 20 x 5 x 8 = 25 x 7 x 4 = 2 x 93 x 5 = 10 x 32 x 2 =

Mental Math # 19 20 x 5 x 8 = 800 25 x 7 x 4 = 700 2 x 93 x 5 = 930

Mental Math # 20 800  20 = 300  50 = 9000  30 = 630  90 = 4200  60 = 7200  800 = 2700  90 = 200  50 = 770  70 = 3200  800 =

Mental Math # 20 800  20 = 40 300  50 = 6 9000  30 = 300 630  90 = 7 4200  60 = 70 7200  800 = 9 2700  90 = 30 2000  50 = 40 770  70 = 11 3200  800 = 4

Mental Math # 21 900  30 = 3600  60 = 2400  30 = 6400  80 = 3600  600 = 35 000  700 = 8000  400 = 4500  50 = 1800  30 = 5600  800 =

Mental Math # 21 900  30 = 30 3600  60 = 60 2400  30 = 80 6400  80 = 80 3600  600 = 6 35 000  700 = 50 8000  400 = 20 4500  50 = 90 1800  30 = 60 5600  800 = 7

Mental Math # 22 480  6 = 3500  70 = 3000  50 = 18 000  60 = 600  60 = 16 000  400 = 8100  900 = 6300  90 = 1200  40 = 3200  800 =

Mental Math # 22 480  6 = 80 3500  70 = 50 3000  50 = 60 18 000  60 = 300 600  60 = 10 16 000  400 = 40 8100  900 = 9 6300  90 = 70 1200  40 = 30 3200  800 = 4

Mental Math # 23 228  2 = 255  5 = 339  3 = 168  4 = 300  50 = 726  6 = 990  90 = 200  5 = 714  7 = 342  3 =

Mental Math # 23 228  2 = 114 255  5 = 51 339  3 = 113 168  4 = 42 300  50 = 6 726  6 = 121 990  90 = 11 200  5 = 40 714  7 = 102 342  3 = 114

Mental Math # 24 530  5 = 369  3 = 322  2 = 464  4 = 600  30 = 816  8 = 8000  40 = 260  5 = 147  7 = 189  9 =

Mental Math # 24 530  5 = 106 369  3 = 123 322  2 = 161 464  4 = 116 600  30 = 20 816  8 = 102 8000  40 = 200 260  5 = 52 147  7 = 21 189  9 = 21

Mental Math # 25 125 + 35 = 2000 + 50 + 400 + 4 = 4.2 + 3 + 0.8 = 23 = $10.00 - $3.85 = 65 + ? = 100 90 x 50 = 135  5 = 100 x 0 .15 = 60 =

Mental Math # 25 125 + 35 = 160 2000 + 50 + 400 + 4 = 2454 4.2 + 3 + 0.8 = 8 23 = 8 $10.00 - $3.85 = $6.15 65 + 35 = 100 90 x 50 = 4500 135  5 = 27 100 x 0.15 = 15 60 = 1

Mental Math # 26 375 + 45 = 200 + 60 + 140 = 31 = 2.7 + 3 + 1.3 = You give $5 for a purchase costing $2.55. What is your change? ? + 275 = 1000 2800 in scientific notation is = 284  2 = 2.9 x 100 = 38.9  10 =

Mental Math # 26 375 + 45 = 420 200 + 60 + 140 = 400 31 = 3 2.7 + 3 + 1.3 = 7 You give $5 for a purchase costing $2.55. What is your change? $2.45 725 + 275 = 1000 2800 in scientific notation is = 2.8 x 103 284  2 = 142 2.9 x 100 = 290 38.9  10 = 3.89

Mental Math # 27 530 + 28 = 2100 + 500 + 230 = 3.5 + 3 + 1.5 = 234.5 in scientific notation = You give $5 for a purchase costing $3.30. What is your change? 300 + 300 + ? = 1000 40 x 500 = 396  3 = 5.3 m equals ___ cm = 82.9  10 =

Mental Math # 27 530 + 28 = 558 2100 + 500 + 230 = 2830 3.5 + 3 + 1.5 = 8 234.5 in scientific notation = 2.345 x 102 You give $5 for a purchase costing $3.30. What is your change? $1.70 300 + 300 + 400 = 1000 40 x 500 = 20 000 396  3 = 132 5.3 m equals 530 cm 82.9  10 = 8.29

Mental Math # 28 200 + 6000 + 3 + 70 = 50 + 3100 + 700 = 32 = 9 + 40.3 + 0.5 = $10.00 - $6.75 = 35 + 25 + ? = 100 3000 x 20 = 350  5 = 237  100 =

Mental Math # 28 200 + 6000 + 3 + 70 = 6273 50 + 3100 + 700 = 3850 32 = 9 9 + 40.3 + 0.5 = 49.8 $10.00 - $6.75 = $3.25 35 + 25 + 40 = 100 3000 x 20 = 60 000 350  5 = 70 237  100 = 2.37 2.304

Mental Math # 29 285 + 65 = 4000 + 7 + 500 + 30 = 6.3 + 0.4 + 1.7 = 285 + 65 = 4000 + 7 + 500 + 30 = 6.3 + 0.4 + 1.7 = 33 = $20.00 - $11.95 = ? + 55 = 200 3 x 700 = 1000  50 = 100 x 0.65 = 636  3

Mental Math # 29 285 + 65 = 350 4000 + 7 + 500 + 30 = 4537 6.3 + 0.4 + 1.7 = 8.4 33 = 27 $20.00 - $11.95 = $8.05 145 + 55 = 200 3 x 700 = 2100 1000  50 = 20 100 x 0.65 = 65 636  3 = 212

Mental Math # 30 75 + 380 = 30 = 4.3 + 3.2 + 1.8 = 1000 - 540 = $100.00 - $59.00 = ? + 85 = 200 200 x 40 = 1000  20 = 100 x 4.5 = 842  2

Mental Math # 30 75 + 380 = 455 30 = 1 4.3 + 3.2 + 1.8 = 9.3 1000 - 540 = 460 $100.00 - $59.00 = $41.00 115 + 85 = 200 200 x 40 = 8000 1000  20 = 50 100 x 4.5 = 450 842  2 = 421

Mental Math # 31 125 + 35 + 75 = 24 = 4.5 + 3.5 + 0.8 = 350 = $10.00 - $3.80 = 65 + ? = 300 90 x 30 = 15cm equals __dm = 1000 x 0.15 = 560  5 =

Mental Math # 31 125 + 35 + 75 = 235 24 = 16 4.5 + 3.5 + 0.8 = 8.8 350 = 1 $10.00 - $3.80 = $6.20 65 + 235 = 300 90 x 30 = 2700 15cm equals 1.5 dm 1000 x 0.15 = 150 560  5 = 112

Mental Math # 32 250 + 125 = 8m equals ___dm 2.3 + 5.8 + 1.7 = 51 = $20.00 - $6.99 = 95 + ? = 300 500 x 70 = 550  5 = 10 x 1 .33 = 361.1  100 =

Mental Math # 32 250 + 125 = 375 8m equals 80 dm = 2.3 + 5.8 + 1.7 = 9.8 51 = 5 $20.00 - $6.99 = $13.01 95 + 205 = 300 500 x 70 = 35 000 550  5 = 110 10 x 1 .33 = 13.3 361.1  100 = 3.611

Mental Math # 33 8 410 000 in scientific notation = 80 = $5.50 + $10 + 2.30 = 10.3 + 4.6 + 0.4 = $10.00 - $2.10 = 350 + 500 + ? = 1000 600 x 3 = 446  4 = 2.11 x 1000 = 762.2  100 =

Mental Math # 33 8 410 000 in scientific notation = 8.41 x 106 80 = 1 $5.50 + $10 + 2.30 = $17.80 10.3 + 4.6 + 0.4 = 15.3 $10.00 - $2.10 = $7.90 350 + 500 + 150 = 1000 600 x 3 = 1800 446  4 = 111 R2 2.11 x 1000 = 2110 762.2  100 = 7.622

Mental Math # 34 355.5 in scientific notation = 90 km equals ____ m 4.1 + 3.6 + 1.9 = 1000 – 230 = $20.00 - $9.90 = 180 + ? = 500 500 x 20 = 559  5 = 10 x 27.3 = 590.1  100 =

Mental Math # 34 355.5 in scientific notation = 3.555 x 102 90km equals 90 000m 4.1 + 3.6 + 1.9 = 9.6 1000 – 230 = 770 $20.00 - $9.90 = $10.10 180 + 320 = 500 500 x 20 = 10 000 559  5 = 111 R4 10 x 27.3 = 273 590.1  100 = 5.901

Mental Math # 35 If = 1, then = 530 000 in scientific notation = 7.95m equals ____cm 4.3 + 2.5 + 1.7 = 1000 – 440 = You give $10.00 for a purchase costing $6.92. What is your change? ? + 275 + 25 = 1000 672  6 = 769.1  10 = 3.4 x 102 =

Mental Math # 35 If = 1, then = 12.3 530 000 in scientific notation = 5.3 x 105 7.95m equals 795cm 4.3 + 2.5 + 1.7 = 8.5 1000 – 440 = 560 You give $10.00 for a purchase costing $6.92. What is your change? $3.08 700 + 275 + 25 = 1000 672  6 = 112 769.1  10 = 76.91 3.4 x 102 = 340

Mental Math # 36 If = 1, then = 385 000 = 5.1 + 5.1 + 7.3 = 9 + 40.3 + 0.5 = $10.00 - $6.75 = 35 + 25 + ? = 100 3000 x 20 = 350  5 = 4.2 x 1000 = 237  10 =

Mental Math # 36 If =1, then = 2.3 385 000 = 3.85 x 105 5.1 + 5.1 + 7.3 = 17.5 9 + 40.3 + 0.5 = 49.8 $10.00 - $6.75 = $3.25 35 + 25 + 40 = 100 3000 x 20 = 60 000 350  5 = 70 4.2 x 1000 = 4200 237  10 = 23.7

Mental Math # 37 Two squared added to three squared = 2L equals ___ mL = 1.5 + 1.5 + 1.5 + 1.6 = 3100 + 200 + 540 = You give $5 for a purchase costing $2.55. What is your change? ? + 275 = 1000 200 x 80 = 384  2 = 2.9 x 100 = 37  10 =

Mental Math # 37 Two squared added to three squared = 13 2L equals 2000 mL = The difference of 52 and 22 = 3100 + 200 + 540 = 3840 You give $5 for a purchase costing $2.55. What is your change? $2.45 725 + 275 = 1000 200 x 80 = 16 000 384  2 = 192 2.9 x 100 = 290 37  10 = 3.7

Mental Math # 38 53 dam = ____ m 2 x 103 = The difference of 52 and 22 = 2 + 5.1 + 1.8 = You give $5 for a purchase costing $3.30. What is your change? 300 + 199 + ? = 1000 40 x 500 = 396  3 = 5.3 x 100 = 82  10 =

Mental Math # 38 53 dam = 530 m 2 x 103 = 2000 The difference of 52 and 22 = 21 2 + 5.1 + 1.8 = 8.9 You give $5 for a purchase costing $3.30. What is your change? $1.70 300 + 199 + 501 = 1000 40 x 500 = 20 000 396  3 = 132 5.3 x 100 = 530 82  10 = 8.2

Mental Math # 39 210 + 163 = 5000 + 660 + 1000 = 5.5 + 5.5 + 5.5 = 2.9 + 4.4 + 0.6 = You give $10 for a purchase costing $5.99. What is your change? 250 + 400 + ? = 1000 50 x 60 = 784  7 = 47.3 x 10 = 2444  100

Mental Math # 39 210 + 163 = 373 5000 + 660 + 1000 = 6660 5.5 + 5.5 + 5.5 = 16.5 2.9 + 4.4 + 0.6 = 7.9 You give $10 for a purchase costing $5.99. What is your change? $4.01 250 + 400 + 350 = 1000 50 x 60 = 3000 784  7 = 112 47.3 x 10 = 473 2444  100 = 24.44

Mental Math # 40 3200 + 543 = 30 + 7000 + 420 = 10 + 5.8 + 3.2 = 8.9 – 4.8 = You give $20 for a purchase costing $1.90 What is your change? 750 + 200 + ? = 1000 90 x 20 = 575  5 = 0.633 x 100 = 71.4  10

Mental Math # 40 3200 + 543 = 3743 30 + 7000 + 420 = 7450 10 + 5.8 + 3.2 = 19 8.9 – 4.8 = 4.1 You give $20 for a purchase costing $1.90 What is your change? $18.10 750 + 200 + 50 = 1000 90 x 20 = 1800 575  5 = 115 0.633 x 100 = 63.3 71.4  10 = 7.14