lesson
Find a number on a line
Read with an adult. You can say, point, draw or write your answer.
1 · Learn
Numbers on a number line stay in order. Equal spaces must mean equal number steps.
On our line every step is one. A number halfway between 40 and 50 is 45 because it is five steps from each end.
An estimate is a sensible rough answer. If we only see marks for 40 and 50, a point just before 50 could be about 48. We say about because we have not measured its exact position.
2 · Worked example
I find 43 by starting at 40 and moving three one-steps to the right. For objects, I can compare an unknown pile with a known group of ten. A pile looking about twice as large might contain about twenty; I count afterwards to check.
3 · Your turn
Which is closer to 50: 48 or 42? Explain. Is an estimate always the exact number?
Check your answer
48 is closer. It is two steps from 50; 42 is eight steps away. No: an estimate is a reasonable rough answer, which we can check by counting or measuring.
4 · Apply your learning
Draw a line marked only at 0, 50 and 100. Your adult places an unlabelled point. Estimate its number together and explain which labelled marks helped. Then estimate a safe pile of counters before counting it; keep both your estimate and count.
Adult guidance and safety
Use practical objects before symbols. Read the task aloud when needed and ask the child to explain, not just name an answer. Revisit with different examples; one successful answer is not proof of fluency.
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