L3 Spring Subtract 1 and 2 Digit Numbers to 20

This Year 1 maths lesson develops children’s understanding of subtraction as counting back using number lines and practical activities. Building on prior learning from Year 1 Spring 1, the lesson begins with a fun, kinaesthetic “frog jumping” starter, where children practise counting back on a number line with single-digit numbers. This engaging approach helps reinforce the concept of subtraction as taking away, preparing pupils for working with larger numbers. In the main teaching input, pupils learn how to subtract a one-digit number from a two-digit number using number lines and counters. The teacher models calculations such as 16 – 5 = 11, showing how to count back in jumps to find the answer. Discussion prompts help children understand that, unlike addition, subtraction is not commutative — meaning the order of numbers cannot be swapped. During the independent activity, children generate their own subtraction number sentences by selecting a two-digit number (10–20) and rolling a die for the one-digit subtrahend. Using rulers or number lines, they count back to find answers and record them in their books, strengthening fluency and reasoning. The plenary encourages deeper understanding through missing number problems (e.g. 14 – ___ = 8 ), showing children how to count back on a number line to find the unknown number and how to check their answers by counting on. Common misconceptions are addressed, including starting from zero, miscounting, or assuming subtraction can be reordered. By the end of the lesson, pupils will have a secure grasp of counting back strategies, an improved understanding of place value, and growing confidence with subtraction within 20.