Quick Sum Estimation Game
Numbers flash up. Round, group and slide to the total.
About Gut Total
Gut Total shows between four and ten numbers on the screen for a few seconds. When they disappear, you slide to the sum of all of them. It is not an exam in adding: you will never have enough time to calculate exactly, and the game does not expect you to. The aim is a good estimate.
On the first levels the numbers are single digits and the sum is easy to approximate. From level 4 the numbers go up to 20, and from about level 7 up to 50. The display time falls from just over four seconds to about two and a third. The tolerance is generous, but the sums grow, so a good strategy matters.
How to play
- Look at the numbers when they appear and decide on a strategy: group, round, or estimate the average and multiply by the count.
- When they disappear, move the slider to your estimate of the total.
- Lock in before the 12 second answer timer ends.
- The real sum is shown on the slider, and the feedback gives your error.
A handful of numbers shows up for a few seconds. Slide to the total of all of them. A good estimate is enough: round the numbers and add them up in groups.
How scoring works
The score is based on the difference between your answer and the real sum. You get 100 for an exact answer, and the score falls in a straight line to 0 at a distance of half the sum on level 1 and about 28 percent of the sum on level 10, with a minimum of 8. So for a sum of 100 on level 10, being off by 14 still earns about 50 points.
The count of numbers rises from 4 to 10 and their size from 1 to 9 on the first levels up to 2 to 50 on the highest. The slider range depends only on the level, never on the sum, so its length does not give the answer away.
What it trains
It trains estimation arithmetic, the skill of getting close with rounding and grouping rather than exact calculation. People use this when they add up a shopping cart, compare prices or check a bill.
It also builds a more flexible relationship with numbers. Studies of mental calculation find that strong estimators use several strategies and choose between them as the numbers change.
Tips for a higher score
- Estimate the average and multiply by how many numbers there are. If seven numbers look like they are around 12, the sum is about 84.
- Group numbers that add up to round values, such as 18 and 2, or 7 and 3. This is called using compatible numbers.
- Round each number to the nearest ten and add. The errors tend to cancel each other.
- Read the numbers from largest to smallest. The big ones decide most of the sum.
- If you run out of time, a rough guess close to the middle of your range beats leaving the slider alone.
The idea behind it
Educators call the techniques behind this game computational estimation. Research by Robert Reys and others in the 1980s identified three main strategies used by good estimators: reformulation (changing the numbers to easier ones), translation (changing the structure of the problem) and compensation (adjusting the result after rounding).
Studies show that estimation skill is not the same as exact calculation skill. Many people who are accurate with pen and paper are less comfortable estimating, which is a reason why the daily practice of quick estimates is a good habit. The approximate number system also seems to be involved when we estimate symbolic quantities.
Frequently asked questions
Do I have to add precisely?
No. The game gives partial points for close answers, so a good estimate is the goal.
How long are the numbers shown?
From about four seconds on level 1 to just over two seconds on level 10, with more numbers on the harder levels.
Which game is related?
Closer To compares calculations with a target, and Number Sense asks you to count numbers that fit a rule.
Related games
Free, no account. Your best scores are saved on your device.