This is a great warmer or activity which is good for teens and adults. In a nutshell, your students must guess how much money is in an imaginary safe.
What to Do
Write a large sum of money, for example, £1,378,354 on a white piece of card and put it in an envelope and seal it. Bring to class.
Draw this on the board:
Tell your students that you are going to draw something on the board. They have to try to guess what it is. Draw a safe on the board, but slowly with pauses, to give time for your students to guess. This will generate interest in the activity. Students usually guess TV or oven first, then safe at the end. They may need to use their phones to get the word, this is OK.
Now show them the envelope and tell your students that inside the safe there is some money (don't tell them how much, just say 'some money'). Tell them that you have written the amount of money in the envelope and that they must guess how much is in there. With sticky tape, stick the envelope on the board next to the safe.
Now ask one more confident student to have a guess. Get their guess from them and then say HIGHER or LOWER. Move on to the next student and take their guess, again say HIGHER or LOWER and then move on.
Soon, you will find that they are really starting to struggle to say higher numbers accurately, and at this point, you can lend help and support to get them to say the numbers they want to say.
Eventually, students will get to the figure, and you can then ask the student which guessed correctly to walk up to the board and open the envelope to show everyone! This is a good warmer and very useful for older students to practice.