Estimating and Mental Math
Round each number to the nearest ten and estimate the sum of 395 and 41.
395 + 41 ≈ 440
43,193 + 12,105
43,193 + 12,105 = 55,298
487,287 - 15,254
487,287 - 15,254 = 472,033
112 + _______ = 4,298
Round each number to the nearest hundred and estimate the difference of 890 and 112.
890 - 112 ≈ 800
82,391 + 39,689
82,391 + 39,689 = 122,080
130,402 - 29,682
130,402 - 29,682 = 100,720
10,000 = 7,291 + _______
2,709
Round each number to the nearest thousand and estimate the sum of 13,932 and 9,930.
13,932 + 9,930 ≈ 24,000
81,049 + 13,239 + 16,575
81,049 + 13,239 + 16,575 = 110,863
60,000 - 6,767
60,000 - 6,767 = 53,233
56,193 - ______ = 20,349
35,844
Round each number to the nearest thousand and estimate the difference of 29,891 - 15,025.
29,891 - 15,025 ≈ 15,000
A teacher taught 4,201 students last year and 599 students this year. How many students did they teach altogether?
They taught 4,800 students altogether.
14,000 - 4,999
14,000 - 4,999 = 9,001
438,650 - ______ = 71,576
367,074
Round each number to the nearest ten thousand and estimate the sum of 143,192 + 67,304 + 9,949.
143,192 + 67,304 + 9,949 ≈ 220,000
Grace paid $2,636 altogether.
An upright piano costs $9,394 less than a grand piano. A grand piano costs $20,000. How much do both pianos cost together?
Both pianos cost $30,606 altogether.