63.7 X 10
637
Estimate the answer:
104 X 0.33
30
4 X 0.27
1.08
0.5 X 0.7
0.35
When estimating, doing this means you estimate a number lower than the actual answer.
Underestimate
94.6 X 103
94,600
Estimate the answer:
0.87 X 112
90
1.35 X 5
6.75
2.4 X 0.7
1.68
When estimating, doing this means you estimate a number higher than the actual answer.
Overestimate
681.7 X 104
6,817,000
Estimate the answer:
0.12 X 105
10
0.35 X 3
1.05
0.2 X 0.8
0.16
Numbers that are easy to compute with mentally are called... (We used to call them "Friendly Numbers.")
Compatible numbers
0.629 X 10_?_ = 62.9
102
Estimate the answer:
99.2 X 82
8,000
40 X 0.22
8.8
11.1 X 0.8
8.88
Products found by breaking one of two factors into ones, tens, hundreds, and so on, and then multiplying each of these by the other factor
Partial Products
1.23 = 10_?_ X 0.123
101
Estimate the answer:
12 X 0.37
3.7 - 4
2.54 X 12
30.48
15.7 X .62
9.734
The number that tells how many times a base number is used as a factor
Exponent