Starter We are Learning to Multiply and Divide

Starter

We are Learning to…… Multiply and Divide Negative Numbers

Multiplying and dividing integers – 3 + – 3 = – 15 – 3 – 12 – 3 – 9 – 3 – 6 – 3 0 5 × – 3 = – 15 A positive number × a negative number = a negative number

Multiplying and dividing negative numbers – 7 × 3 = 3 × – 7 = – 21 – 7 – 7 – 14 – 7 0 A negative number × a positive number = a negative number

Multiplying and dividing negative numbers – 4 × – 6 = 24 0 – – 6 6 12 – – 6 18 24 A negative number × a negative number = a positive number

Ordered multiplication square

Rules for multiplying and dividing When multiplying negative numbers remember: positive × positive = positive × negative = negative × positive = negative × negative = positive Dividing is the inverse operation to multiplying. When we are dividing negative numbers similar rules apply: positive ÷ positive = positive ÷ negative = negative ÷ positive = negative ÷ negative = positive

Multiplying and dividing integers Complete the following: – 3 × 8 = – 24 – 36 ÷ 42 ÷ – 7 = – 6 540 ÷ – 90 = – 6 – 12 × – 8 = 96 – 7 × – 25 = 175 47 × – 4 × – 5 × – 8 = – 160 3 = 141 – 72 ÷ – 6 = 12 9 = – 4 3 × – 8 ÷ – 16 = 1. 5

Using a calculator We can enter negative numbers into a calculator by using the sign change key: (–) For example: – 417 ÷ – 0. 6 can be entered as: (–) 4 1 7 ÷ (–) 0 . 6 = The answer will be displayed as 695. Always make sure that answers given by a calculator are sensible.

Mixed multiplication square

Mixed division square

Integer cards – multiplication and division

Number spiral -2 -8 -10 × 2 ÷ -5 2 4 × -1 3 + -11 -5 -7 -4 -15 0 + × 5 16 -2 + -3 ÷ -2 6 8

• To succeed at this lesson today you need to… • 1. Work out the multiplications and divisions • 2. Choose the missing cards to make the sums correct • 3. Explain why some of the answers are wrong in the questions Foundation Plus Page 9 Ex N 1. 4

Homework