Addition and Subtraction - Efficient subtraction - Starter

The 'Efficient subtraction' starter activity, aimed at Year 4 students during the Autumn Term's seventh week, day two, is designed to strengthen their subtraction skills through a series of exercises. The students are tasked with solving subtraction problems using the formal method, which involves lining up numbers by their place value and subtracting one digit at a time from right to left. One of the problems presented is '71 – 47 =', and after calculating, the students are encouraged to use the inverse operation to verify their answers. This process is demonstrated with the calculation '786 – 392 = 391', followed by checking '391 + 392' to see if it equals '786'. However, the check reveals an error, as the correct answer should be '394'.

Another part of the activity includes a real-life application question where a runner has jogged 6/11 of a mile towards his house. Students must figure out how much further he has to go to complete the mile. The activity also presents a larger subtraction problem: 'Subtract one thousand, one hundred and ninety-six from eight thousand, nine hundred and eighty-three', where students are again prompted to use the inverse operation to check their work. Additionally, students are given a problem in a worded format: '2 tens and seventy-seven subtract 2 ones and four tens', which translates to a numerical subtraction problem they need to solve. Through these exercises, students practice their subtraction skills, ensuring they understand both the process and the importance of checking their work for accuracy.