234 + 500 – 21 420 – 632 + 324 Can you work these out? = 713 = 112 Collect Homework Can you work these out? = 713 234 + 500 – 21 420 – 632 + 324 = 112

L.O. To be able to work out mixed addition and subtraction expressions By the end of the lesson we will be able to: understand that the sign in front of a number tells you what to do with that number identify when we can work out a mixed sum by going left to right identify when we must change the order to work out a mixed sum

What must you remember? You must remember that it is the sign IN FRONT of the number that tells you what to do with that number! If the sign is plus you must add that number to the rest If the sign is minus you must take that number away from the rest

You can add and take away in ANY ORDER Example 138 + 76 – 94 To 138 we must add 76 and take away 94 We can do the operations in any order but we MUST START WITH THE FIRST NUMBER !!! I can add 76 first then take away 94 138 + 76 = 214 214 – 94 = 120 I can take away 94 first then add 76 138 – 94 = 44 44 + 76 = 120

Example: 42 – 70 + 51 - 3 We must start with 42 but we can add and take away in any order Notice that we can’t take away 70 first so we must choose a different order here! We can do the operations in any order but we MUST START WITH THE FIRST NUMBER !!! I can add 51 then take away 3 and 70 42 + 51 = 93 93 – 3 = 90 90 – 70 = 20 I can take away 3 first then add 51 and take away 70 42 - 3 = 39 39 + 51 = 90 90 – 70 = 20

Example: 95 – 161 + 75 +10 We must start with 95 but we can add and take away in any order Notice that we can’t take away 161 first so we must choose a different order! We can do the operations in any order but we MUST START WITH THE FIRST NUMBER !!! I can add 75 first then take away 161 and add 10 95 + 75 = 170 170 – 161 = 9 9 + 10 = 19 I can add 10 first then 75 then take away 161 95 + 10 = 105 105 + 75 = 180 180 – 161 = 19

Mixed addition & subtraction You MUST ALWAYS start with the FIRST number To this first number you can then add or take away in any order The sign IN FRONT of the number tells you what to do with that number

Suggestion.. If you can work the sum in the order that it is given, then do it ! If you can’t, then remember that the sign in front tells you what to do with the number!

Bingo Activity Time CHOOSE ANY 6 NUMBERS 30 20 95 13 597 144 25 129 83 5 4 CHOOSE 6 NUMBERS

14 + 2 – 8 – 3 14 + 2 = 16 16 – 8 = 8 8 – 3 = 5 If you chose 5  cross it off!

36 – 24 + 62 - 49 36 - 24 = 12 12 + 62 = 74 74 – 49 = 25 If you chose 25  cross it off!

361 – 200 + 15 – 81 361 – 200 = 161 161 + 15 = 176 176 – 81 = 95 If you chose 95  cross it off!

29 + 108 – 210 + 93 29 + 108 = 137 137 + 93 = 230 230 – 210 = 20 If you chose 20  cross it off!

105 + 23 – 78 – 50 105 + 23 = 128 128 – 78 = 50 50 – 50 = 0 If you chose 0  cross it off!

23 – 2 + 4 + 5 23 - 2 = 21 21 + 4 = 25 25 +5 = 30 If you chose 30  cross it off!

952 – 1010 – 251 + 438 952 + 438 = 1390 1390 - 1010 = 380 380 – 251 = 129 If you chose 129  cross it off!

27 + 6 – 11 – 9 27 + 6 = 33 33 – 11 = 22 22 – 9 = 13 If you chose 13  cross it off!

17 + 4 – 9 – 3 – 5 17 + 4 = 21 21 – 9 = 12 12 – 3 = 9 9 – 5 = 4 If you chose 4  cross it off!

If you chose 144  cross it off! Find the difference between one hundred and ninety, and eighty-three. Then add on thirty-seven 190 – 83 = 107 107 + 37 = 144 If you chose 144  cross it off!

124 + 51 – 78 – 14 124 + 51 = 175 175 – 78 = 97 97 – 14 = 83 If you chose 83  cross it off!

612 – 318 + 219 + 84 612 – 318 = 294 294 + 219 = 513 513 + 84 = 597 If you chose 597  cross it off!

L.O. To be able to work out mixed addition and subtraction expressions By the end of the lesson we will be able to: understand that the sign in front of a number tells you what to do with that number identify when we can work out a mixed sum by going left to right identify when we must change the order to work out a mixed sum

Homework for Tomorrow STP 7 Pg 9 Exercise 1f 1,11,13,17,19,21,29(p10)