HT weekly challenge

Calling all maths whizzes . . . . this is the page where you can gain extra good marks in KS2 and rewards in KS1 . . . . can you answer the puzzles?? Answers will be shared in assembly each week . . . let the competition begin!

Mensa Brain Teaser:

Assume you are using a basic calculator and press the numbers in the order shown, replacing each question mark with a mathematical sign. Plus, minus, multiply and divide can each be used once only.

What are the highest and lowest numbers you can possibly score?