How should I track my progress?
You improve what you measure. Mental math has a few clean metrics, and tracking them honestly tells you whether your practice is working or just keeping you busy.
SIXTY scores each sprint in correct answers per minute, alongside accuracy and seconds per problem, and lists the facts you missed. Together these give you a full picture: how fast, how clean, and exactly where to aim next.
Which metrics actually matter?
Three. Correct answers per minute (cpm) is your headline fluency number. Accuracy is the share of attempts you got right. Seconds per problem is the inverse view of speed, useful for spotting hesitation.
Watch them together. High accuracy with low cpm means you are careful but slow. High cpm with low accuracy means you are rushing. The goal is to push cpm up while keeping accuracy high.
Why is cpm better than raw correct count?
A raw count rewards anyone who simply spends more time. Correct answers per minute normalizes for time, so it measures fluency rather than endurance.
It also blends speed and accuracy into one honest number: wrong answers do not count, and slow answers cost you the minute. If you guess fast, your accuracy drops and cpm stalls; if you crawl carefully, the clock caps you. Only genuine recall raises it.
Should I judge myself on a single session?
No. Any one sprint is noisy — sleep, focus, and which facts happened to come up all swing the result. A single bad run means little, and a single great run is not yet a habit.
Read the trend across many sessions instead. Look at where your cpm sits over the last two weeks versus the prior two. A line that drifts upward, even slowly, is the signal; day-to-day bounce is just noise.
How do I use my list of missed facts?
Your missed-facts list is the most actionable thing on the results screen. It names the exact problems that are dragging your accuracy and slowing your cpm.
Treat that list as your study set. The facts that recur across sessions are your true weak spots, not the one-off slips. Drill those specifically, then watch whether they stop appearing — that is direct evidence your practice is landing.
When should I raise the difficulty?
Raise difficulty when your current level feels comfortable: accuracy is consistently high and your cpm has flattened because you already know the material cold. Coasting on easy facts stops teaching you anything.
Bump it up by one notch, expect cpm to dip at first, and let it climb back as the new facts automate. If accuracy collapses, you went too far — step back one level and build from there.
How do SIXTY's benchmark tiers fit in?
The tiers — Developing under 15 cpm, Fluent 20 to 30, Strong 30 to 40, Elite 40 and up — are directional markers, not grades. They tell you roughly where you stand and what a meaningful next step looks like.
Use them to set a target, then forget them mid-session and just answer. Chasing a tier number while you solve only adds pressure; let the score reflect the work afterward.
Reading is review. Recall is what sticks.
Start a 60-second sprint →