Addition and Subtraction - Inverse Operations - Starter

The mathematics lesson for Year 5, set in the Autumn Term's fifth week, day three, challenges students with a variety of problems to test their understanding of inverse operations, specifically within the context of addition and subtraction. Students begin with a 'Fluent in Four' revision exercise, where they are tasked with multiplying nine by twenty-two, which equals one hundred and ninety-eight. Then, they move on to solve word problems that require them to calculate and show their workings in their books. One such problem involves Si, who is planning to replace his fence and must estimate the total length of his old fence by adding the lengths of all four sides, which are given in centimetres. The sides are 1,234 cm, 2,543 cm, 1,234 cm, and 2,543 cm respectively. By rounding each side to the nearest thousand, students simplify the problem to find an approximate total length of 8,000 cm.

Another problem presented is for Esin, who needs to calculate the length of wire required to enclose her rabbit's pen. The pen's dimensions are provided in metres, with each side measuring 6m or 4m. Students must add the lengths of all sides to find the total perimeter, which is 36 metres. The final task involves Jonathan, who has been shopping for clothes in a half-price sale. Students must work out the total cost of his purchases during the sale, which comes to £18.50, and then determine what the total would have been at full price, which is £37.00 or 3,700 pence. This exercise not only tests their arithmetic skills but also their ability to understand discounts and value for money.