Question

name and *
date
fall
math review
1 circle the numbers that are odd
4 28 91 15 19 20
7 36 44 33 71 10
2 how can you tell if a number is even.

3 solve using doubles.
__+=12 +__=16
__+=8 +__=6
solve using doubles + 1.
__++ 1=15 +__+1=5
__++1=17 +__+1=19

Explanation:

Question 1: Circle the numbers that are odd

Odd numbers are integers that are not divisible by 2, i.e., when divided by 2, they leave a remainder of 1. Let's check each number:

• 4: \( 4 \div 2 = 2 \) with remainder 0 → even
• 28: \( 28 \div 2 = 14 \) with remainder 0 → even
• 91: \( 91 \div 2 = 45 \) with remainder 1 → odd
• 15: \( 15 \div 2 = 7 \) with remainder 1 → odd
• 19: \( 19 \div 2 = 9 \) with remainder 1 → odd
• 20: \( 20 \div 2 = 10 \) with remainder 0 → even
• 7: \( 7 \div 2 = 3 \) with remainder 1 → odd
• 36: \( 36 \div 2 = 18 \) with remainder 0 → even
• 44: \( 44 \div 2 = 22 \) with remainder 0 → even
• 33: \( 33 \div 2 = 16 \) with remainder 1 → odd
• 71: \( 71 \div 2 = 35 \) with remainder 1 → odd
• 10: \( 10 \div 2 = 5 \) with remainder 0 → even

A number is even if it is divisible by 2 without leaving a remainder. In other words, when a number is divided by 2, the remainder is 0. For example, 4, 28, 20, 36, 44, 10 are even because \( 4 \div 2 = 2 \), \( 28 \div 2 = 14 \), etc., with remainder 0. Also, even numbers can be identified by their last digit: if the last digit is 0, 2, 4, 6, or 8, the number is even.

Let the number be \( x \). Then \( x + x = 12 \) → \( 2x = 12 \) → \( x = \frac{12}{2} = 6 \). So \( 6 + 6 = 12 \).

Answer:

Circle the numbers: 91, 15, 19, 7, 33, 71

Question 2: How can you tell if a number is even?