Estimating sums

math

1. Estimating Sum

2. Terms
•Sum–Answer to addition.
•Addends–The numbers that are being
added
•Estimate–An estimate to the answer of a
problem; it tells you whether the answer is
the tenths, ones, tens, hundreds,
thousands . . .

3. Steps
•Sample Problem: 14 + 17 = ?
•Round each of the addends so that there
is one number followed by zero(es).
Ex. 14 -> 10
+ 17 -> 20
•Solve the estimate to find the place value
of the sum.
10 + 20 = 30; the answer is in the tens.
14 + 17 = 31; the actual sum

4. Additional Practice
1.18 + 21 =
2.27 + 6,245
3.99 + 21
4.22 + 28
1.20 + 20 = 40
The answer is in the hundreds.
2. 30 + 6,000 = 6,030
The answer is in the thousands.
3. 100 + 20 = 120
The answer is in the hundreds
4. 20 + 30 = 50
The answer is in the tens

5. 568 187
+ 27 + 56
1648 16
+ 43 + 13
600
+ 30
630
2000
+ 40
2,040
200
+ 60
260
20
+ 10
30

6. Let’s try this together.
337 71 4381 634
+ 13 + 13 + 41+ 12