Subtraction Concepts and Methods

This video tutorial teaches how to subtract two-digit numbers using addition. It begins with a review of subtraction concepts and demonstrates how to model subtraction with base 10 blocks. The tutorial explains the counting up method, where subtraction problems are rewritten as addition sentences. It also introduces the use of open number lines to find sums and differences. The video addresses common misconceptions about place value and provides examples of subtraction by counting up. The lesson concludes with a summary of the techniques covered.

What is the main concept introduced in this lesson?

• Subtracting using multiplication

• Subtracting using addition

• Adding using subtraction

• Multiplying using division

When subtracting 32 from 47 using base 10 blocks, what is the result?

• 10

• 20

• 25

• 15

How can an open number line help in subtraction?

• By allowing jumps in thousands

• By allowing jumps in tens or ones

• By allowing jumps in fives

• By allowing jumps in hundreds

What is a common misunderstanding about the number 87?

• The 8 is seen as 80

• The 8 is seen as 8

• The 7 is seen as 7

• The 7 is seen as 70

In the example of subtracting 63 minus 32, what is the final difference?

• 21

• 51

• 31

• 41

What is the first step in subtracting 86 minus 27 by counting up?

• Jump to the nearest 5

• Jump to the nearest 10

• Jump to the nearest 20

• Jump to the nearest 50

How many more do you need to add to 27 to reach 86?

• 49

• 59

• 79

• 69

What is the benefit of counting up by multiples of 10?

• It makes subtraction impossible

• It makes subtraction harder

• It decreases the number of hops

• It increases the number of hops

What is the result of 86 minus 27 using the counting up method?

• 79

• 69

• 59

• 49

What is the final step in the counting up method for subtraction?

• Add the hops

• Subtract the hops

• Divide the hops

• Multiply the hops