Addition and subtraction - Subtract with two-digit numbers not crossing 10 - Planning

The Year 2 Autumn Addition and Subtraction curriculum, in its fourth week, introduces students to the concept of subtracting two-digit numbers without crossing the number 10. This foundational skill is essential before moving on to more complex subtraction problems that involve borrowing from the tens place. The lesson utilises a variety of resources, including Base 10 blocks, place value grids, worksheets, and a presentation, to ensure that children can visualise and understand the subtraction process. Key vocabulary such as 'subtraction', 'take away', 'pounds', 'pence', 'equals', 'more', 'less', 'tens', and 'ones' are emphasised to build a solid mathematical language foundation. Students are encouraged to use concrete materials and draw representations of Base 10, which aids in independent problem-solving and helps clarify the misconception that both numbers in a calculation need to be built.

During the lesson, children engage in partner work and practical activities that guide them through the process of subtracting by partitioning numbers into tens and ones. For example, when subtracting 34 from 78, students learn to partition and subtract the individual place values before combining them to find the final answer. The lesson also introduces the column method, using real-life contexts such as spending money to solidify the concept. Differentiated worksheets and activities cater to various learning levels, from those working towards expectations, to those at the expected level, and even those working at greater depth. The lesson concludes with a plenary session that addresses common misconceptions, such as subtracting tens before ones or having an insecure understanding of place value. By the end of the lesson, students should be comfortable with subtracting two-digit numbers without crossing 10 and be able to articulate their understanding using the provided stem sentences and resources.