1. Sarah had 80 cupcakes to sell at a bake sale. She sold 70 cupcakes. Then Sarah’s mom brought 20 more cupcakes for Sarah to sell at the bake sale. Which expression can be used to find out how many cupcakes, c, Sarah now has?
2. Last week, Lucas had 55 marbles. He lost some marbles when he dropped his marble bag outside. Now Lucas has 32 marbles. Which equation can be used to show the amount of marbles, m, that Lucas lost?
3. What is the sum of 7 and 6?
4. What is the sum of 9 and 5?
5. Which pair of equal numbers add to 16?
6. Which equation can be used to determine the number of squares to the right?
7. 8 hundreds, 5 tens, and 3 ones is equivalent to which number?
8. Ten tens is the same as which number?
- one thousand
- one hundred
9. Bosco started counting to 1000. He said “5, 10, 15, 20, …” Was Bosco counting by 5s, 10s, 100s, or 1000s?
10. How is the number 645 read in expanded form?
- six hundred fifty-four
- six hundred forty-five
- six thousand forty-five
- six thousand four hundred fifty
Answers and Explanations
1. A: Sarah started with 80 cupcakes, and she sold 70, so the expression 80-70 can be used to represent the number of cupcakes she had before her mom brought more to sell. Because her mom brought 20 more cupcakes to the bake sale, 20 is added to the previous expression. The equation which represents the number of cupcakes, c, Sarah has after selling 70 cupcakes and receiving 20 more is 80-70+20=c.
2. A: Lucas began with 55 marbles, so the expression should begin with 55 marbles. Because he lost m marbles, m should be subtracted from the 55. So the expression 55-m can be used to show how many marbles Luca has now. The problem states that he now has 32 marbles, so the 55-m is equal to 32. Therefore, the equation which represents this scenario is 55-m=32.
3. C: If 7 items and 6 items were placed side-by-side and all of the items were counted, there would be 13 items.
4. D: If 9 items and 5 items were placed side-by-side and all of the items were counted, there would be 14 items.
5. B: 7+7=14; 8+8=16; 9+9=18; and 10+10=20. Only 8+8 adds to 16 from this group of numbers.
6. B: Because there are 5 columns and 4 rows, 5 is added 4 times to find the number of squares. The resulting equation is 5+5+5+5=20.
7. A: An 8 in the hundreds spot means it is the third digit from the right. A 5 in the tens spot means it is the second digit from the right, and a 3 in the ones spot means it is the digit on the far right. The final answer is 853.
8. D: Because ten is a 1 with a 0 behind it, or 10; ten tens is a 10 with a 0 behind it, or 100. This number is one hundred. The sum of ten tens is one hundred.
9. A: Because the difference between each consecutive number is 5; that is 10-5=5,15-10=5, and 20-15=5, Bosco is counting by 5s.
10. B: A 6 in the third digit from the right is six hundred. The 4 in the tens spot is forty, and a 5 in the ones spot is five. The final answer is six hundred forty-five.