Estimation Station

What your child will figure out

• Estimate a visible quantity by grouping rather than counting every item.
• Estimate a length by comparing it with a visible benchmark.
• Round two or three addends to friendly tens or hundreds and combine them to estimate a sum.
• Use an estimate to reject unreasonable claimed totals across repeated transfer challenges, then refine accuracy through adaptive practice.

The levels

1. The candy jar

   Predict about how many candies are visible, reveal 37, and explain how groups of about ten support 40.

2. Rocket ribbon

   Estimate a prize rocket against a ruler benchmark, reveal 68 cm, and explain why 70 cm is sensible.

3. Ticket total

   Round 48 and 73 to friendly tens, estimate 120, reveal 121, and explain the round-then-add strategy.

4. Button barrel

   Build an estimate of 86 from visible groups and distinguish a supported estimate from counting or guessing.

5. Banner stretch

   Estimate 143 cm by coordinating 100 cm and nearby ten-centimetre benchmarks.

6. Two prize counters

   Round 126 and 278 to tens and combine 130 + 280 to estimate 410.

7. The impossible jackpot

   Transfer estimation to a reasonableness check and reject the claim that 198 + 304 is about 900.

8. Packed token drum

   Estimate 146 with tighter choices by using rows, chunks, and gaps rather than one-by-one counting.

9. Pennant line

   Estimate 92 cm with close choices by adjusting down from a 100 cm benchmark.

10. Hundreds headliner

    Round 347 and 582 to hundreds and use 300 + 600 to estimate 900.

11. Double-or-nothing sign

    Use 600 + 400 to reject the claim that 612 + 389 is about 1,600.

12. Grand midway total

    Transfer rounding to three addends by estimating 249 + 451 + 318 as 1,000.