Embed Size (px)
Citation preview
© 2007 M. Tallman
© 2007 M. Tallman
4 × 0.3
= 1.2
© 2007 M. Tallman
3 × 0.25
= 0.75
© 2007 M. Tallman
2.5 × 4
Step 1: Line up the lowest places (not the decimals).
Step 2: Multiply as usual.
Step 3: Add the number of decimal places in both factors.
2.5 4
45
×
Step 4: The product must have the same number of decimal places.
.2
001
21
Decimal Place
0 Decimal
Place
1 + 0 = 1.
4 x 5 = 204 x 2 = 88 + 2 = 10
© 2007 M. Tallman
Step 1: Line up the lowest places (not the decimals).
61491
32366.
32.36 × 6
Step 2: Multiply as usual.
Step 3: Add the number of decimal places in both factors.
32.36 6
Step 4: The product must have the same number of decimal places.
×
3212
Decimal Places
0 Decimal
Place
2 + 0 = 2.
6 x 6 = 366 x 3 = 1818 + 3 = 216 x 2 = 12
12 + 2 = 146 x 3 = 1818 + 1 = 19
© 2007 M. Tallman
© 2007 M. Tallman
10 = 10 × 10 × 10 × 10 × 10 = 5
10 = 10 × 10 × 10 × 10 = 4
10 = 10 × 10 × 10 = 3
10 = 10 × 10 = 2
10 = 1 = 0
10 = 10 = 1
Power of ten- a number that can be written as 10 raised to some
exponent. 100,000
10,000
1,000
100
10
1
© 2007 M. Tallman
1,000 × 12.5 = 12,500.
1 × 12.5 = 12.510 × 12.5 = 125.
100 × 12.5 = 1,250.
What pattern do you notice?
10,000 × 12.5 = 125,000.
© 2007 M. Tallman
10,000 × 0.0007 = 7.
1 × 0.0007 = 0.000710 × 0.0007 = 0.007100 × 0.0007 = 0.07
1,000 × 0.0007 = 0.7
© 2007 M. Tallman
Thousands Hundreds Tens Ones TenthsHundredth
sThousandt
hs
009 × 10 = 90200 × 10 =
2,00080 × 10 = 800289 × 10 = 2,890289 × 10 = 2,890
289 ×289 × 1100Multiplying by 10 means every digit must
move left by 1 place
22 88 99Fill in the empty space in the ones place with a zero.
© 2007 M. Tallman
.4 × 100 = 407 × 100 = 70050 × 100 = 5,000
.03 × 100 = 357.43 × 100 = 5,74357.43 × 100 = 5,743
Thousands Hundreds Tens Ones TenthsHundredth
sThousandt
hs
57.43 ×57.43 × 110000Multiplying by 100 means every digit must
move left by 2 places
55 77 44 33
© 2007 M. Tallman
.6 × 100 = 602 × 100 = 20030 × 100 = 3,000
32.607 × 100 = 3,260.732.607 × 100 = 3,260.7.00 × 100 = 0.007 × 100 = .7
Thousands Hundreds Tens Ones TenthsHundredth
sThousandt
hs
32.607 ×32.607 × 110000Multiplying by 100 means every digit must
move left by 2 places
33 22 66 00 77
© 2007 M. Tallman
.5 × 1,000 = 500
8 × 1,000 = 8,000
8.546 × 1,000 = 8,5468.546 × 1,000 = 8,546.04 × 1,000 = 40.006 × 1,000 = 6
Thousands Hundreds Tens Ones TenthsHundredth
sThousandt
hs
8.546 ×8.546 × 1,1,000000Multiplying by 1,000 means every digit must
move left by 3 places
88 55 44 66
© 2007 M. Tallman
0.007 × 1,000 = 70.007 × 1,000 = 7.007 × 1,000 = 7
Thousands Hundreds Tens Ones TenthsHundredth
sThousandt
hs
0.007 ×0.007 × 1,1,000000Multiplying by 1,000 means every digit must
move left by 3 places
77
© 2007 M. Tallman
8 × 100 = 80030 × 100 = 3,000
38 × 100 = 3,80038 × 100 = 3,800
Thousands Hundreds Tens Ones TenthsHundredth
sThousandt
hs
38 ×38 × 110000Multiplying by 100 means every digit must
move left by 2 places
33 88Fill in the empty space in the ones place with a zero.
00 00
© 2007 M. Tallman
0.2 × 100 = 205 × 100 = 5005.2 × 100 = 5205.2 × 100 = 520
Thousands Hundreds Tens Ones TenthsHundredth
sThousandt
hs
5.2 ×5.2 × 110000Multiplying by 100 means every digit must
move left by 2 places
55 2200Fill in the empty space in the ones place with a zero.
© 2007 M. Tallman
0.05 × 100 = 50.9 × 100 = 900.95 × 100 = 950.95 × 100 = 95
Thousands Hundreds Tens Ones TenthsHundredth
sThousandt
hs
0.95 ×0.95 × 110000Multiplying by 100 means every digit must
move left by 2 places
99 55
© 2007 M. Tallman
1. 10 × 19 =1. 10 × 19 =
2. 652 × 10 =2. 652 × 10 =
3. 10,000 × 8.2 =3. 10,000 × 8.2 =
4. 32.6 × 10 = 4. 32.6 × 10 =
5. 100 × 135.9 = 5. 100 × 135.9 =
190
6,520
82,000
326
13,590
© 2007 M. Tallman
6. 91.671 × 10 =6. 91.671 × 10 =
7. 10 × 1,664.9 =7. 10 × 1,664.9 =
8. 54 × 1,000 = 8. 54 × 1,000 =
9. 1,000 × 6.5 = 9. 1,000 × 6.5 =
10. 1234.567 × 100 =10. 1234.567 × 100 =
123,456.7
6,500
916.71
16,649
54,000
