By Fatskills Exam Guides Team — the exam nerds behind 28,500+ quizzes and 2.1M practice questions across 500+ global exams.
By the end of this topic, students will be able to: - Understand the concept of place value and its significance in comparing numbers. - Identify and write numbers in tens and ones. - Compare numbers using a variety of methods, including counting on and counting back. - Recognize and explain the relationship between tens and ones. - Use mental maths to compare numbers within 100.
Place value is a way of understanding the value of each digit in a number. The value of a digit depends on its position in the number. In a two-digit number, the left digit represents tens and the right digit represents ones.
For example, in the number 45, the 4 represents 40 (4 tens) and the 5 represents 5 (5 ones).
To compare numbers, we can use counting on and counting back. Counting on means adding a certain number of tens or ones to a number, while counting back means subtracting a certain number of tens or ones.
For example, to compare 45 and 50, we can count on 5 ones from 45 to get 50.
Sarah has 45 pencils in her pencil case. Her friend, Emily, has 50 pencils. How many more pencils does Emily have than Sarah?
To solve this problem, we can count on 5 ones from 45 to get 50. Since Emily has 50 and Sarah has 45, Emily has 5 more pencils than Sarah.
A bookshelf has 25 books on it. If 15 more books are added, how many books will the bookshelf have in total?
To solve this problem, we can count on 15 ones from 25 to get 40. Since 15 ones is equal to 1 ten and 5 ones, we can add 1 ten and 5 ones to 25 to get 40.
To overcome these misconceptions, teachers can use visual aids such as number lines and hundreds charts to help students understand the concept of place value. Teachers can also use real-life examples, such as counting money or measuring lengths, to help students understand the relationship between tens and ones.
What is the value of the digit 4 in the number 45?
A) 4 ones B) 4 tens C) 40 D) 5
Correct answer: B) 4 tens Why the distractors fail: A) is incorrect because 4 ones would equal 4, not 40. C) is incorrect because 40 is the value of the number 4 in the number 45, not the value of the digit 4. D) is incorrect because 5 is the value of the digit 5 in the number 45, not the value of the digit 4.
A) 30 B) 40 C) 25 D) 35
Correct answer: B) 40 Why the distractors fail: A) is incorrect because 30 is 5 less than 35, not 15 more than 25. C) is incorrect because 25 is the original number of books, not the total number of books after adding 15 more. D) is incorrect because 35 is 10 more than 25, not 15 more.
What is the next number in the sequence: 10, 20, 30, 40, ?
A) 50 B) 60 C) 70 D) 80
Correct answer: A) 50 Why the distractors fail: B) is incorrect because 60 is 10 more than 50, not the next number in the sequence. C) is incorrect because 70 is 20 more than 50, not the next number in the sequence. D) is incorrect because 80 is 30 more than 50, not the next number in the sequence.
A toy car costs £25. If a 10% discount is applied, how much will the toy car cost?
A) £20 B) £22.50 C) £25 D) £27.50
Correct answer: B) £22.50 Why the distractors fail: A) is incorrect because 10% of £25 is £2.50, not £5. C) is incorrect because no discount has been applied. D) is incorrect because the discount is 10%, not 50%.
What is the value of the digit 5 in the number 56?
A) 5 tens B) 5 ones C) 50 D) 6
Correct answer: B) 5 ones Why the distractors fail: A) is incorrect because 5 tens would equal 50, not 56. C) is incorrect because 50 is the value of the number 5 in the number 56, not the value of the digit 5. D) is incorrect because 6 is the value of the digit 6 in the number 56, not the value of the digit 5.
(Answer should be 3 tens)
(Answer should be 40)
(Answer should be 50)
(Answer should be £22.50)
(Answer should be 9 ones)
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