Subtraction Strategies with Base 10

Holly Russell, a second-grade teacher, explains the expand and trade subtraction strategy using base 10 models. She demonstrates the method with two examples: a two-digit subtraction (68 minus 17) and a three-digit subtraction (143 minus 65). The video emphasizes the visual aspect of the strategy, allowing students to see the trades they make. Holly also suggests watching a video on base 10 shorthand for better understanding.

What is the main topic of Holly Russell's video?

• Multiplication with base 10

• Expand and trade subtraction strategy

• Addition using base 10 models

• Division using everyday math

What is the first subtraction problem discussed in the video?

• 143 minus 65

• 68 minus 17

• 200 minus 75

• 100 minus 50

How is the number 68 represented in the video?

• Using base 2 shorthand

• Using base 5 shorthand

• Using base 10 shorthand

• Using base 20 shorthand

What does Holly do to subtract 17 from 68?

• Adds 17 to 68

• Crosses out one group of ten and seven ones

• Divides 68 by 17

• Multiplies 68 by 17

What is the result of 68 minus 17?

• 71

• 81

• 61

• 51

What is the three-digit subtraction problem introduced in the video?

• 175 minus 85

• 150 minus 75

• 143 minus 65

• 200 minus 100

Why is trading necessary in the three-digit problem?

• Because there are not enough groups of ten and ones

• Because subtraction is not possible

• Because addition is required

• Because there are enough groups of ten

What is the first trade made in the three-digit problem?

• Trading a group of 20 for two groups of ten

• Trading a group of 100 for ten groups of ten

• Trading a group of ten for ten ones

• Trading a group of 50 for five groups of ten

What is the second trade made in the three-digit problem?

• Trading a group of ten for ten ones

• Trading a group of 50 for five groups of ten

• Trading a group of 20 for two groups of ten

• Trading a group of 100 for ten groups of ten

How many groups of ten are subtracted in the three-digit problem?

• Four groups of ten

• Five groups of ten

• Seven groups of ten

• Six groups of ten