Weekly Problem

Last week’s answer: Two sides are 4cm long and the other two are 5cm long. To work this out, you need to think of two numbers which add together to make 9 (half of 18) and multiply together to make 20. 4 and 5 are these numbers.

This week’s problem: Pedro builds a function machine. When the numbers 2 and 4 are put in, the machine gives 10. When 5 and 7 are put in, the machine gives 37. What will the machine give if 4 and 5 are put in?

The answer will be in next week’s weekly problem.

Last week’s answer: 25cm. If 6 bricks are 10cm high, then 3 bricks are 5cm high. This means the tower will be 5 x 5 = 25 cm tall, as there are 5 lots of 3 bricks in 15 bricks.

This week’s problem: The perimeter of a rectangle is 18cm and its area is 20cm^2. How long are the sides of this rectangle?

The answer will be in next week’s weekly problem.

Last week’s answer: 9:12 am. This can be done in two ways – writing down the times at which each train will return to the station and finding the first time on both, or calculating the LCM of 4 and 6 (12) and then adding that to 9am.

This week’s problem: Don is building a tower out of small bricks. It will be 15 blocks high. So far 6 bricks have been placed, which reach a height of 10cm. How tall will the complete tower be?

The answer will be in next week’s weekly problem.

Last week’s answer: 1.2112. The sum of two numbers is the same as adding them together, and this addition requires some careful place value.

This week’s problem: Two toy trains, A and B, leave the station at 9am. Train A takes 4 minutes to complete 1 circuit of the track, and Train B takes 6 minutes to complete 1 circuit of the track. What time will both trains meet again at the station?

The answer will be in next week’s weekly problem.

Last week’s answer: 45cm. On Friday the plant will be 20 + 10 = 30cm tall, and on Saturday the plant will be 30 + 15 = 45cm tall.

This week’s problem: Find the sum of 1.13 and 0.0812.

The answer will be in next week’s weekly problem.

Last week’s answer: 240m. This is because there are 8 spaces between the lamp posts, each of which is 30m long.

This week’s problem: Hans has planted a flower, and every day the flower is one and a half times as tall as it was the day before. On Thursday it is 20cm tall. How tall will it be on Saturday?

The answer will be in next week’s weekly problem.

Last week’s answer: 2228. This is a tricky column subtraction, with a lot of carrying digits.

This week’s problem: 9 lamp posts in a row are spaced 30m apart. What is the distance between the first and last lamp post?

The answer will be in next week’s weekly problem.

Last week’s answer: 25m^2. Each side of the square is 20/4 = 5m, and therefore the area of the garden is 5×5=25m^2.

This week’s problem: What is 7013 – 4785? Do not use a calculator.

The answer will be in next week’s weekly problem.

Last week’s answer: 8. You can use a letter, such as x, to represent the number, or you can do the operations in reverse on 10.

This week’s problem: I have a garden wall that surrounds my whole garden, which is a square. The wall is 20m long. What is the area of my garden?

The answer will be in next week’s weekly problem.

Last week’s answer: €55. Multiply the amount (£50) by the ratio of the prices (1.1).

This week’s problem: Ahmed thinks of a number. He multiplies it by 4, takes away 2 and divides by 3. He gets 10. What was his original number?

The answer will be in next week’s weekly problem.