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Grade 5

Mixed additions

Lesson

Strategies for addition

There are many ways to tackle addition problems, so having a few to choose from means we can pick the one prefer. Sometimes, the type of problem means one method is much more suitable. 

Adding two numbers together

Let's start by adding only two numbers together. We can look for patterns in addition, use a place value table, use a vertical algorithm, and even partition our numbers. In video 1, we work through some examples, and place value turns out to be very useful. We even use the bridge to $10$10 strategy in one problem. Then we'll solve one problem three different ways!

Practice question

Question 1

Evaluate $786+692$786+692

Adding more than two numbers

In Video 2, we're going to think about how to choose a strategy that works best for addition problems. When it comes to adding several numbers together, writing the problem in a vertical algorithm, or down the page, is ideal. Let's work through one of these, and then perform a quick check, to see if our answer seems reasonable.

 

Remember!

There are many ways to solve addition problems, so remember to think of place value, partitioning numbers, bridging to 10, and any patterns that exist.

Practice questions

Question 2

Evaluate $563+771+439$563+771+439

  1. $\editable{}$ $\editable{}$ $\editable{}$  
      $5$5 $6$6 $3$3
    + $7$7 $7$7 $1$1
    + $4$4 $3$3 $9$9
    $\editable{}$ $\editable{}$ $\editable{}$ $\editable{}$

Question 3

Evaluate $15+6236+973+8428$15+6236+973+8428.

Outcomes

5.NN3.01

Solve problems involving the addition, subtraction, and multiplication of whole numbers, using a variety of mental strategies (e.g., use the commutative property: 5 x 18 x 2 = 5 x 2 x 18, which gives 10 x 18 = 180)

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