What is a key characteristic of a numerical expression?

• It always includes an equal sign.

• It contains numbers and operation signs but no equal sign.

• It only includes numbers.

• It is a complete mathematical equation.

If Emma has 11 fish and buys 4 more, which expression represents this situation?

• 11 - 4

• 11 + 4

• 11 x 4

• 11 / 4

Lucia has 128 stamps and uses 38. What expression represents the remaining stamps?

• 128 x 38

• 128 / 38

• 128 + 38

• 128 - 38

Carla buys 5 books, each costing $3. Which expression shows the total cost?

• 5 x 3

• 5 + 3

• 5 - 3

• 5 / 3

How do parentheses affect the expression: 20 - (12 + 3)?

• They indicate that 12 and 3 should be added first.

• They indicate that 20 should be subtracted first.

• They have no effect on the order of operations.

• They suggest multiplication of 12 and 3.

Doug spends $15 each day for 3 days, with $5 left each day. How is this represented?

• 3 + (15 - 5)

• 3 x (15 - 5)

• 15 - 5 x 3

• 15 x 3 - 5

Kim spends $12 on a pole and finds $3. Which expression matches this?

• 20 - 12 - 3

• 20 - 12 + 3

• 20 + (12 - 3)

• 20 - (12 + 3)

Terry had 18 worms, gave 4 to Susie and 3 to Jamie. Which expression is correct?

• 18 + 4 - 3

• 18 + (4 + 3)

• 18 - (4 + 3)

• 18 - 4 + 3

Rick had $8 and earned $5 per hour for 4 hours. Which expression shows his total money?

• 8 + (4 + 5)

• 8 x 4 + 5

• 8 + 4 + 5

• 8 + 4 x 5

What is the main focus of this lesson on numerical expressions?

• Learning advanced algebraic concepts.

• Understanding and writing numerical expressions.

• Solving equations with equal signs.

• Memorizing mathematical formulas.