Rounding to the Nearest Tens
Rounding to the Nearest Hundreds
Estimating Sums and Differences
Front End Estimation
Is It Reasonable?
100
Round 32 to the nearest ten.
What is 30?
100
Round 95 to the nearest hundred.
What is 100?
100
72-34=
What is 70-30=40?
100
721+145=
What is 700+100=800
100
25+56 30+60=90
What reasonable?
200
Round 147 to the nearest tens.
What is 150?
200
Round 251 to the nearest hundred.
What is 300?
200
462+236=
What is 500+200=00
200
421+256=
What is 400+200=600?
200
73+81 70+80=150
What is reasonable?
300
Round 653 to the nearest tens.
What is 650?
300
Round 789 to the nearest hundred.
What is 800?
300
562+124=
What is 600+100=700
300
621+3,904=
What is 600+3,000=3,600
300
52+103= 60+110=170
What is not reasonable?
400
Round 203 to the nearest tens.
What is 200
400
Round 4,624 to the nearest hundred.
What is 4,600?
400
621-374=
What is 600-400=200
400
5,689+3,495=
What is 5,000+3,000=8,000?
400
Using front end estimation; 9,254-3,521 9,000-4,000=5,000
What is not reasonable? It should be 9,000-5,000.
500
Round 4,421 to the nearest ten.
What is 4,420?
500
Round 6,021 to the nearest hundred.
What is 6,000
500
7,210+2,100=
What is 7,200+2,100=9,300
500
8,624-4,261=
What is 8,000=4,000=4,000?
500
Use front end estimation. 4,621+4,721 4,000+4,000=8,000
What is reasonable?
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