Use addition and subtraction to solve problems in different contexts
I can use addition and subtraction strategies to solve problems in different contexts.
Use addition and subtraction to solve problems in different contexts
I can use addition and subtraction strategies to solve problems in different contexts.
Lesson details
Key learning points
- By looking carefully at the numbers involved, you can choose the most efficient strategy.
- When numbers are close together, finding the difference is the most efficient strategy.
- Sometimes, we can use known addition facts to make finding the difference even more efficient.
Keywords
Minuend - The minuend is the number being subtracted from.
Subtrahend - A subtrahend is a number subtracted from another.
Difference - The difference is the result after subtracting one number from another.
Partition - Partition is the act of splitting an object or value down into smaller parts.
Common misconception
On the magic squares, children will often miss the fact that it is a two step problem involving addition and subtraction. They may think you have to add the two numbers in the row/column or diagonal.
Start with a simpler magic square. The easier ones feature the numbers 1-9 and total 15 diagonally, vertically or horizontally. Once they understand them, introduce 2-digit and 3-digit magic squares.
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Complete the missing word _______ − subtrahend = difference
Q2.What is the missing part in this bar model?
Q3.Which of the pairs of numbers have a difference of 60?
Q4.Which of these is the correct equation represented by this number line?
Q5.Look at the number line. Which number is missing from the equation? 670 − 150 =
Q6.Look at the number line. Which number is missing from the equation? 220 + = 480
Assessment exit quiz
6 Questions
Q1.Choose the correct equation for this word problem: Laura has baked 15 cupcakes. She gives 7 of them to her friends. How many does she have left?
Q2.Use an efficient strategy to solve this problem: In one year, the local council plants 420 trees. The next year, they plant 190 more. How many trees have been planted over the two years? trees
Q3.Use an efficient strategy to solve this problem: In a science experiment, Aisha makes 440 g of slime. Laura makes 270 g of slime. They mix their slime together. How much slime is there now? g
Q4.Use an efficient strategy to solve this problem: Aisha pours herself 330 ml of squash. Laura kindly pours in 95 ml more before Aisha drinks 58 ml. How much squash does she have left? ml
Q5.What is the top value of the top brick in this addition pyramid?
Q6.Find the missing number in the magic addition square. All the rows, columns and diagonals add up to 300
