This rounding to the nearest 10 game helps third graders learn to round two-digit numbers by playing: race cars, pop balloons, flip memory cards or sprint through true and false sentences. Each question gives a number from 11 to 99, such as 47 or 82, and children pick the nearest ten from four choices that sit next to each other on the number line. It is free, needs no sign-up, works on phones and tablets, and comes with a printable rounding chart with number lines.
Rounding to the nearest 10 game: see how it plays
The game below has four modes, and every question asks for the nearest ten. The printable chart shows the rule, three number lines and eight numbers to round, and the pictures show Answer Race, Balloon Pop and True or False on this page.
How the rounding to the nearest 10 game works
- Answer Race: every right answer moves your car forward, and you race three computer cars to the finish flag. The first to 15 wins, and wrong taps cost time, not places.
- Balloon Pop: answers float up on balloons, and you pop the right one before it drifts off the top. Every balloon is a ten, and the wrong ones are the tens next to the right answer, so children must pick the nearest ten and not just any ten. The game speeds up as your score climbs, and three misses ends the round.
- Memory Match: twelve face-down cards hide six numbers to round and their six answers. Flip two at a time and match each one to its answer in as few moves as you can.
- True or False: sixty seconds on the clock. Decide whether each sentence, such as Round 31 to the nearest 10 = 30, is right or wrong. A streak of five or more scores double.
Rounding numbers game: what the rounding to the nearest 10 game asks
The game picks a number from 11 to 99 and never asks a number that ends in 5, so the first practice is on clear cases where the number is plainly nearer one ten than the other. That leaves 80 different numbers, and 8 of them are already tens, such as 40, which round to themselves. Here is every number in the game, grouped by the ten it rounds to:
| Rounds to | Numbers in the game | How many |
|---|---|---|
| 10 | 11, 12, 13, 14 | 4 |
| 20 | 16, 17, 18, 19, 20, 21, 22, 23, 24 | 9 |
| 30 | 26, 27, 28, 29, 30, 31, 32, 33, 34 | 9 |
| 40 | 36, 37, 38, 39, 40, 41, 42, 43, 44 | 9 |
| 50 | 46, 47, 48, 49, 50, 51, 52, 53, 54 | 9 |
| 60 | 56, 57, 58, 59, 60, 61, 62, 63, 64 | 9 |
| 70 | 66, 67, 68, 69, 70, 71, 72, 73, 74 | 9 |
| 80 | 76, 77, 78, 79, 80, 81, 82, 83, 84 | 9 |
| 90 | 86, 87, 88, 89, 90, 91, 92, 93, 94 | 9 |
| 100 | 96, 97, 98, 99 | 4 |
Rounding to the nearest ten in three steps
- Find the tens that sit on each side. 47 is between 40 and 50.
- Look at the ones digit. If it is 0 to 4, round down. If it is 5 to 9, round up.
- Write the ten. The ones digit becomes 0 and, when rounding up, the tens digit goes up by one.
| Number | Thinking | Rounded |
|---|---|---|
| 23 | Ones digit 3, so round down | 20 |
| 68 | Ones digit 8, so round up | 70 |
| 41 | Ones digit 1, so round down | 40 |
| 96 | Ones digit 6, so round up | 100 |
| 30 | Already a ten, so it stays | 30 |
| 54 | Ones digit 4, so round down | 50 |
In the rounding to the nearest 10 game the halfway case, such as 35 or 75, is by convention rounded up. The game leaves it out at first, so children learn the clear cases before the rule for the middle. Wikipedia’s rounding article describes this and other rounding conventions.
Why a number line helps with rounding
The rounding to the nearest 10 game becomes much easier with a picture. Put 43 on a number line from 40 to 50. The midpoint is 45, and 43 is to the left of it, so 43 is closer to 40. The picture makes the rule “5 or more, round up” make sense, because 45 is the middle of the hill and everything past it rolls down to 50. The printable chart shows 43, 47 and 75 on number lines for this reason. Our number line maker prints blank lines for practice, and the hundreds chart shows the tens as columns.
Rounding to 10 game: grade 3 rounding and the number line printable
The rounding to 10 game is a grade 3 rounding warm-up that takes about five minutes. After a round, print the rounding number line printable and ask children to mark three numbers from the game, such as 46, 62 and 88, and draw an arrow to the nearest ten. Seeing the arrow makes grade 3 rounding concrete, and a child who can draw the arrow can usually explain the rule. The rounding game is also a good way to prepare for rounding to 100.
Why children round: estimating
- Quick checks: 38 + 41 is about 40 + 40 = 80, so an answer of 790 is clearly wrong.
- Shopping: a toy at $19 is about $20, so three toys cost about $60.
- Measuring: a plant of 52 cm is about 50 cm tall.
- Population and distance: news and maps use rounded numbers because exact ones are hard to say.
Where rounding to 10 fits at school
| Level | What children are expected to do |
|---|---|
| Grade 3 (US) | Use place value understanding to round whole numbers to the nearest 10 or 100 (3.NBT.A.1) |
| Grade 4 (US) | Round multi-digit whole numbers to any place (4.NBT.A.3) |
| Year 3 (England) | Estimate and round numbers to the nearest 10 and 100 |
The Common Core grade 3 number and operations in base ten standards name this skill. For written work, see the printable worksheets.
Rounding to the nearest 10 game: frequently asked questions
What grade is rounding to the nearest 10 game practice for?
Grade 3 in the United States and Year 3 in England, usually ages 8 and 9, though some schools start in grade 2.
What is the rule for rounding to the nearest 10?
In the rounding to the nearest 10 game and on paper, look at the ones digit. If it is 0 to 4, round down to the ten below. If it is 5 to 9, round up to the ten above.
Does 5 round up or down?
The usual rule is that 5 rounds up, so 35 rounds to 40. The rounding to the nearest 10 game does not ask numbers that end in 5.
Why are the wrong answers also tens?
So that children have to work out which ten is nearest and cannot pick the answer just because it ends in 0.
Is the rounding to the nearest 10 game free, and do kids need an account?
Yes, it is free, and no account is needed. Best scores are saved only in the browser on this device.
Does it work on phones and tablets?
Yes. Every game is built for touch first and also works with a mouse on a computer.