Today is rung 2 of 7 on this topic
Multi-step problems, and estimating first
Can do: Solves two- and three-step problems and estimates the answer before calculating.
Why it matters
Estimation is the error-catcher. A child who estimates first notices when a slip has produced an answer ten times too big.
What it looks like when it's wobbly
Writes an answer with no sense of whether it's plausible, and never notices a decimal-point-sized error.
⏱️ Two-minute check
"Four boxes of 24 pens, 30 are used. Roughly how many left? Now work it out exactly."
Solid looks like: An estimate around 70 before calculating, then 66 exactly.
The full activity for this topic · 15 minutes
Guess Then Check
- 1Read the problem and estimate out loud first, rounding everything.
- 2Write the estimate down where it can't be quietly abandoned.
- 3Solve it properly, showing the steps.
- 4Compare to the estimate: "Is this close to what we expected?"
- 5If it's miles off, find the error rather than accepting the answer.
If it's too hard
One-step problems with rounding to the nearest ten.
If it's too easy
Three steps, with one piece of information in the problem that isn't needed.
Say this
"Before you work it out — roughly what should the answer be? Now check yourself."