Page 121 - New Medley 3 Semester 1
P. 121
4. + 6140 = 6140 + 1224
5. + 1263 = + 4419
6. 3252 + = + 2146
7. [4219 + 1363] + 1047 = 4219 + [ + 1047]
8. [2152 + 3258] + 3041 = 2152 + [3258 + ]
9. [ 4175 + 1621] + = 4175 + [1621 + 2047]
10. [2074 + 1072] + 3041 = + [1072 + 3041]
11. [ + 1024 ]+ 3074 = 1004 + [1024 + 3074]
12. [1207 + ] + 4128 = 1207 + [2214 + 4128]
13. 2352 + 0 =
14. 4252 + = 4252
15. + 2435 = 2435
16. 0 + = 3169
17. + 0 = 3679
18. 0 + 2457 =
Estimating Sum
A post-office received 2376 parcels in the first week and 3142 parcels in
the second week. Let us estimate the total number of parcels received in
the two weeks by rounding to nearest tens.
2376 rounds to 2380 2 3 8 0
3142 rounds to 3140 + 3 1 4 0
5 5 2 0
2376 + 3142 ≈ 2380 + 3140 = 5520
The post-office received nearly 5520 parcels.
We can also estimate the sum by rounding to nearest hundreds and
thousands.
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