Calculating flexibly

Today we will learn to estimate using derived facts and then adjust them to calculate the answer. We will then be able to solve a range of problems selecting suitable strategies and giving reasons for our choices.

This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Quiz:

Intro quiz - Recap from previous lesson

Before we start this lesson, let’s see what you can remember from this topic. Here’s a quick quiz!

Question 1

Question 2

Question 3

Question 4

Question 5

Q1.Which of the following methods for answering a multiplication questions is NOT a mental strategy?

Short multiplication Array models Blank number line Marked number line

1/5

Q2.Today we discussed distributive law in relation to multiplication. But which of the following number sentences does NOT correctly represent distributive law?

32 x 7 = 30 x 7 + 2 x 7 13 x 24 = 10 x 24 + 3 x 24 26 x 14 = 20 x 10 + 6 x 4 19 x 17 = 19 x 10 + 19 x 5 + 19 x 2

2/5

Q3.Which of the following representations would be efficient for the calculation 317 x 23?

Array models Cuisenaire Rods Dienes

3/5

Q4.For which of these calculations would you consider using a mental strategy and NOT a written method?

923 x 6 910 x 12 572 x 6 456 x 7

4/5

Q5.Which calculation do the dienes represent?

63 x 6 13 x 6 16 x 6 603 x 6

5/5

This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Quiz:

Intro quiz - Recap from previous lesson

Before we start this lesson, let’s see what you can remember from this topic. Here’s a quick quiz!

Question 1

Question 2

Question 3

Question 4

Question 5

Q1.Which of the following methods for answering a multiplication questions is NOT a mental strategy?

Short multiplication Array models Blank number line Marked number line

1/5

Q2.Today we discussed distributive law in relation to multiplication. But which of the following number sentences does NOT correctly represent distributive law?

32 x 7 = 30 x 7 + 2 x 7 13 x 24 = 10 x 24 + 3 x 24 26 x 14 = 20 x 10 + 6 x 4 19 x 17 = 19 x 10 + 19 x 5 + 19 x 2

2/5

Q3.Which of the following representations would be efficient for the calculation 317 x 23?

Array models Cuisenaire Rods Dienes

3/5

Q4.For which of these calculations would you consider using a mental strategy and NOT a written method?

923 x 6 910 x 12 572 x 6 456 x 7

4/5

Q5.Which calculation do the dienes represent?

63 x 6 13 x 6 16 x 6 603 x 6

5/5

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This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Quiz:

Calculating Flexibly Quiz

What a super learner you are! Being able to estimate and calculate within the same lesson, you deserve a big pat on the back for a job well done! However, our lessons are never over until you have completed the quiz. This will be a great opportunity to see how much of the information has embedded and how confident you will be to calculate flexibly in the future. Good luck.

Question 1

Question 2

Question 3

Question 4

Question 5

Q1.Which of the following number sentences would be the most efficient choice to use when estimating 237 x 4

230 x 4 235 x 4 240 x 4 200 x 4

1/5

Q2.Which estimation is correct for the calculation 192 ÷ 8?

192 ÷ 10 190 ÷ 8 200 ÷ 8 200 ÷ 10

2/5

Q3.During the lesson today, Daniel created an area model to help with his mental strategies. But he forgot to record the calculation! Can you identify the original question?

87 x 5 90 x 5 93 x 5 100 x 5

3/5

Q4.I rounded a calculation and got the estimated answer of 560. But what was my original sum?

131 x 4 109 x 4 138 x 4 152 x 4

4/5

Q5.Which of the following calculations would provide you with the value indicated on the marked number line after it is rounded to create an estimated answer?

104 x 7 152 x 5 197 x 4 72 x 11

5/5

This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Quiz:

Calculating Flexibly Quiz

Question 1

Question 2

Question 3

Question 4

Question 5

Q1.Which of the following number sentences would be the most efficient choice to use when estimating 237 x 4

230 x 4 235 x 4 240 x 4 200 x 4

1/5

Q2.Which estimation is correct for the calculation 192 ÷ 8?

192 ÷ 10 190 ÷ 8 200 ÷ 8 200 ÷ 10

2/5

Q3.During the lesson today, Daniel created an area model to help with his mental strategies. But he forgot to record the calculation! Can you identify the original question?

87 x 5 90 x 5 93 x 5 100 x 5

3/5

Q4.I rounded a calculation and got the estimated answer of 560. But what was my original sum?

131 x 4 109 x 4 138 x 4 152 x 4

4/5

Q5.Which of the following calculations would provide you with the value indicated on the marked number line after it is rounded to create an estimated answer?

104 x 7 152 x 5 197 x 4 72 x 11

5/5

Lesson summary: Calculating flexibly

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The next lesson in Multiplication and division is "Short multiplication"

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