Year 7 Calculator Challenge Lesson

Getting to know your calculator Look at your calculator What is the difference between the scientific calculator and the ones you have used before? How can each key have more than one function?

How will you deal with the brackets on your calculator? Brackets-a-go-go How many different ways can you use brackets to create different values for this expression? 7 x 4 + 8 ÷ 2 – 1 How would you use brackets to give these values? How will you deal with the brackets on your calculator? = 31 = 35 = 84 = 49 = 41 = 17 Are there any more values that the calculation can have?  

Multiple Digit Magic 444 4 + 4 + 4 = 12 444 ÷ 12 = ? Write a 3-digit number where all the digits are the same. Add up the digits. Divide the 3-digit number by the sum of the digits. Record the quotient (answer). Repeat with other numbers. What do you notice? Why do you think this happens? 444 4 + 4 + 4 = 12 444 ÷ 12 = ? I noticed that …. I think this happens because …

Multiple Digit Magic What if we think of the number as nnn? Can we use place value to think about the number? How can thinking about this help us to explain what is happening? Can we enter nnn into the calculator??? I noticed that …. I think this happens because …

Be Square! Which numbers can be expressed as the sum of two squares? 5 = 4 + 1 = 22 + 12 Which of these numbers can also be expressed as the sum of 2 squares? 14 25 6 26 122 40 153 21 56 102 53 77 123 164 72 35 99 65 64 5 51 43 104 55 29 130 27 16 148 125 34 22 140 20 36 19 13 100 90 9 49 73 160 82 109 17 50 103

Rooting it Out! How accurately can you estimate the square roots of numbers? What strategies can you use to estimate the square root of a number? What maths do you think the key is doing?

Beyond Integers: Call that a number? Is the following statement always, sometimes or never true? Explain your reasoning. ‘Addition and multiplication make numbers bigger, subtraction and division make numbers smaller.’ What count as ‘numbers’? What do we mean by ‘bigger’ and ‘smaller’? How do we describe the different values in an expression or calculation?

Beyond Integers: The key keys Is the following statement always, sometimes or never true? Explain your reasoning. ‘Addition and multiplication make numbers bigger, subtraction and division make numbers smaller.’ Pressing this key before entering a value will make the value negative This key will allow you to enter fractions into the calculator Shift and this key will allow you to enter mixed numbers Use the arrow keys to move the cursor to the correct part of the fraction or mixed number This key (toggle key) allows you to switch between fraction and decimal answers

Beyond Integers: Call that a number? ‘Addition and multiplication make numbers bigger, subtraction and division make numbers smaller.’ I think the statement is always/sometimes/never true because … Here is the evidence to support my answer: Use the language in the table to complete the sentence in as may ways as you can If the numbers being are then the will always be added multiplied subtracted divided   whole numbers greater than 1 less than 1 fractions decimals mixed numbers sum product difference quotient resulting value result greater than the initial number smaller than the initial number smaller than 1 greater than the dividend smaller than the multiplicand

Beyond Integers: Call that a number? Is the following statement always, sometimes or never true? Explain your reasoning. ‘Addition and multiplication make numbers bigger, subtraction and division make numbers smaller.’ I think the statement is always/sometimes/never true because … Here is the evidence to support my answer:

I think …. When you are working with a friend, use these to explain what you are thinking … It could be this because … It can’t be this because … If we do this then … I wonder what will happen if … I know this so … It’s an even number … It’s bigger than … … if we multiply by 10 then … It’s smaller than … … the answer has to be … It’s an odd number …

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