Daily Estimate
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Number Line Place a number on an open line, then see how close you were. 
Magnitude Match Which is greater? Put them in order. How far apart? Harder as the numbers get closer. 
Decimal Duel Which is larger — 0.45 or 0.5? Predict, then watch both land on a tenths line. 
Number Duel Flash-count dots and pick the smartest strategy — 2–4 players, one device or an online room by code. All activities
Sharpen your number sense
Number Line Place a number on an open line, then see how close you were. Magnitude Match Which is greater? Put them in order. How far apart? Harder as the numbers get closer. Decimal Duel Beat the “longer means bigger” trap — predict which decimal is larger, then watch them land on a tenths line. Mental Math Dojo Pick the strategy the numbers beg for, then work it out. Subitizing Flash Name how many dots you saw — without counting. Bundle Tens Build a number with base-ten blocks, or bundle a loose pile into standard form — ten ones make one ten, and the value never changes. Commit Number Draw digits one at a time and lock each into a place slot before you see the next — no take-backs — to build the biggest number or land closest to a target. A place-value strategy game. Benchmark Lens Judge which friendly landmark a number is nearest. Your calibration See if you guess high or low, and watch it get sharper over time.
Play together
Think it through first
More ways to play
Same idea, another world
😄 Brain break
Meet the cast — the characters who teach this
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Estimator Ernie Confidently approximate; the first-guess advocate -
Pivot Pia Deceptively casual question-flipper; reframes the prompt -
Ratio Rio Per-something specialist; rate thinker -
Splitter Sasha Make-10 and place-value specialist; benchmark builder -
Nudge Nora Compensation — nudge a number to a friendly round one, do the easy math, then give back exactly what you borrowed. -
Doubler Della Doubling and halving — to multiply, double one number and halve the other; the product stays the same while one side gets friendlier. -
Landmark Lena Benchmark numbers — judge any number by how it sits next to friendly landmarks like 0, a half, 10, 50, and 100. -
Factor Fiona Factors and multiples — every number is built from smaller numbers multiplied together, and seeing the building blocks makes hard arithmetic come apart. -
Gap Gus Constant difference — subtraction is the gap between two numbers; slide both the same amount and the gap stays the same, so you can land on friendly numbers. -
Bridge Bao Derived facts — reach a fact you don't know by taking one short step out from a fact you do.
Ensemble stories — the cast together