Tiêu đề [Read Only] MO B003 V2 - Solutions.pdf ✅

New Century School Maths Olympiad Yr3 and Yr4 - V2 1 Yr3 and Yr4 Maths Olympiad Practice B003 - V2 Solutions Part 1 – Basics Part 2 – Achieve High 1. 20 × 20 = 400 Exercise A 30 × 30 = 900 1. 702 is therefore between 400 and 900. To get the last digit of 2, let’s try 21 and 22 or 23 and 24 or 26 and 27. 21 and 22 is not possible since the first number must be an even number. 2. Within the range of 400 and 900, 702 is closer to the 900. So let’s try 26 and 27: 26 × 27 = 702 The numbers on the two open pages are 26 and 27. Exercise B 1. 2. 60 × 60 = 3600 70 × 70 = 4900 4160 is therefore between 3600 and 4900. To get the last digit of 0, let’s try 64 and 65 or 65 and 66. 2. 65 and 66 is not possible since the first number must be an even number. Let’s try 65 and 66: 65 × 66 = 4160 The numbers on the two open pages are 64 and 65. Exercise C 1. 3. 80 × 80 = 6400 90 × 90 = 8100 7482 is therefore between 6400 and 8100. To get the last digit of 2, let’s try 81 and 82 or 83 and 84 or 86 and 87. Within the range of 6400 and 8100, 7482 is closer to the 8100. 2. So let’s try 86 and 87: 86 × 87 = 7482 The numbers on the two open pages are 86 and 87.