Find the two tens the number sits between, then look at the ones digit: 5 or more rounds up, less than 5 rounds down. For hundreds, look at the tens digit.
roundchange to a nearby, easier number
nearest tenthe closest number ending in 0
nearest hundredthe closest number ending in 00
estimatea close guess
Watch for: Looking at the wrong digit, like the tens when rounding to the nearest ten. Rounding 846 to 800 when the question asks for the nearest ten. Rounding a 5 down: 45 rounds up to 50.
At home: Round prices at the shop: is $3.72 closer to $3 or $4? Is 68 closer to 60 or 70?
Sample sheet and answer key
Luna's Space Adventure
Grade 3 · Rounding to 10 and 100 · 3.NBT.A.1
NameDate
Astronaut Luna is exploring a far-off corner of space. Solve each problem to help Luna's mission go smoothly!
Which ten is closer?
Mark 43. Is it closer to 40 or 50?
Nearest ten
Five or more rounds up.
738 rounds to730740
189 rounds to180190
96 rounds to90100
592 rounds to590600
539 rounds to530540
327 rounds to320330
249 rounds to240250
106 rounds to100110
823 rounds to820830
542 rounds to540550
Nearest hundred
Look at the tens digit.
108 rounds to100200
881 rounds to800900
186 rounds to100200
233 rounds to200300
774 rounds to700800
850 rounds to800900
706 rounds to700800
310 rounds to300400
Sheet
Luna's Space Adventure
Grade 3 · Rounding to 10 and 100 · 3.NBT.A.1
Answer key
Astronaut Luna is exploring a far-off corner of space. Solve each problem to help Luna's mission go smoothly!
Which ten is closer?
Mark 43. Is it closer to 40 or 50?
Nearest ten
Five or more rounds up.
738 rounds to730740
189 rounds to180190
96 rounds to90100
592 rounds to590600
539 rounds to530540
327 rounds to320330
249 rounds to240250
106 rounds to100110
823 rounds to820830
542 rounds to540550
Nearest hundred
Look at the tens digit.
108 rounds to100200
881 rounds to800900
186 rounds to100200
233 rounds to200300
774 rounds to700800
850 rounds to800900
706 rounds to700800
310 rounds to300400
Answer key
New problems every time, three levels (gentle, core and stretch), themes to pick from, a second page if you want one. Each sheet comes with an answer key and a one-page guide for grown-ups.
