L5 Spring Identify One More & One Less

Working Without Worksheets – Year 1 Place Value: One More and One Less within 20 This Working Without Worksheets lesson helps Year 1 pupils master the skill of finding one more and one less within 20. Using number lines, counting objects, and stem sentences, children develop fluency in reasoning about numbers and build secure foundations for addition and subtraction. The lesson begins with a starter activity: Recap prior learning from the previous lesson and Autumn Term. Revisit spelling number words up to 20 by showing incomplete words. Children fill in the missing letters on their whiteboards before checking with the animated slides. Highlight common pitfalls in spelling teen numbers (e.g. remembering ee in fifteen rather than just e ). In the main input, pupils explore one more and one less using the number line: Place a counter on number 13 and ask: “What will happen if I want to find one more?” and “What about one less?” Model moving the counter forwards and backwards to find the answers. Provide stem sentences such as: “One more than 13 is 14. One less than 13 is 12.” Give children number lines (and counting objects where needed) to practise with their own numbers. Explore carefully worded examples, such as: “One less than ___ is 19”. Discuss how this is asking for one more than 19, not one less! Work through these examples to avoid misconceptions. For the independent activity, children demonstrate their understanding in books: Each child picks a digit card from 1–20 and represents it using counting objects. Write the numeral, then remove one object to show one less or add one to show one more. Record the results in books. Challenge task: children glue in a paper number line, circle a number, and complete the stem sentences: “One more than my number is ___.” “One less than my number is ___.” The plenary reinforces reasoning: Show examples on the board with missing numbers (e.g. “One less than 12 is ___” ). Children explain their answers using the number