Addition and subtraction - Subtract with two-digit numbers crossing 10 - Starter

In this engaging session tailored for Year 2 pupils, the focus is on mastering subtraction with two-digit numbers, particularly crossing the threshold of ten. The lesson is part of the Autumn Term's curriculum, specifically Week 8, Day 4. It begins with a 'Fluent in Four' revision exercise that prompts students to fill in the blanks and perform calculations to build their fluency in arithmetic. For example, they are tasked with solving equations such as '30 ÷ 10' and '26 ÷ 2', which require basic division skills. The activity is designed to warm up their mathematical thinking and prepare them for the main subtraction challenges ahead.

The core of the lesson involves subtracting two-digit numbers where students must cross over a ten. They are invited to compare quantities, such as '84 – 42', and break down these numbers into tens and ones to simplify the process. This decomposition technique helps them understand that '8 tens – 4 tens' results in '4 tens', and '4 ones – 2 ones' yields '2 ones', leading to the conclusion that '84 – 42' equals '42'. Additionally, the students are encouraged to order groups of numbers from smallest to greatest and to complete number sentences by determining whether the amounts are greater than, equal to, or less than each other. These exercises enhance their comprehension of numerical value and the relationship between numbers, which is fundamental in developing a solid mathematical foundation.