Word problems
Mia has 12 stickers. Her friend gives her 5 more. How many stickers does Mia have now?
17 (12+5=17)
What is 6+6? What type of fact is this?
12; doubles
What is 9+0? What happens to a number when you add 0?
9. The number stays the same.
How many beads are on this rack altogether? (picture 1)
20 (10+10)
Is 8 odd or even? Write an addition equation that shows two equal groups.
4+4=8
There are 38 students' books on a shelf. The teacher adds 20 more books. How many books are on the shelf now?
58 (38+20=58)
Solve 8+5 by starting at 8 and counting on. What type of fact is this?
13 (9,10,11,12,13); count on
Solve 4+10. What happens when you add 10 to a number?
14. The ones digit stays the same, and the number increases by 10.
Some beads are covered. How many beads are hidden, and how many are visible?
13 hidden, 7 visible
Is 13 odd or even? Imagine putting the objects into pairs. What happens?
Odd. Six pairs can be made, and one would be left without a pair.
There are 46 crayons in a box. Lavelle uses 18 crayons. How many crayons are left now?
28 (46-18=28)
You know that 7+7 is 14. Use that doubles fact to solve 7+8. What type of fact is this?
15 (7+7+1=15)
Solve 6+9 by thinking about adding 10 first.
15. Think 6+10 = 16, then subtract 1 to get 15 (because 9 is one less than 10).
The first row shows 8 visible beads. How many more beads are needed to make 10?
2 (8+2=10)
Aiden has 6 pairs of mittens. How many individual mittens are there? Is the total odd or even? Write an equation.
12 mittens, even. 6+6=12
There are 27 students on the playground. Another 16 students join them. Then 9 students go inside. How many students are still on the playground?
34 (27+16=43; 43-9=34)
Solve 8+6 by making ten. How many do you move from the 6 to the 8? How can you show this strategy?
14. Move 2 from the 6 to the 8 to make 10+4=14
You know 8+8=16. Use that doubles fact to solve 8+7.
15. Doubles minus one
There are 15 beads showing on this rack, and 4 covered. If 6 beads were covered, how many beads would still be showing? Explain with an equation.
14 visible, 6 covered (20-6=14)
There are 17 students in Ms. Vaughn's classroom. Three more students arrive, then 4 students leave. How many students are still in the classroom? Is the final total odd or even?
16 students, even. 17+3=20; 20-4=16
44 (35+28=63; 63-19=44)
Solve 15-7. Explain how knowing 7+8=15 helps you with this problem.
7+8=15 so 15-7=8 (Subtraction is the opposite of addition)
Solve 9+8 in two different ways: use a make ten strategy AND a doubles strategy.
17. Make ten: 10+7=17. Doubles: 8+8=16, then add 1
Mario sees 9 beads in the first row and knows there are 10 beads in each row. Mario adds 6 more beads. What is the total number of beads being counted? Explain using a make 10 fact.
15. Make 10 by moving 1 from the 6 to the 9, to make 10+5=15
Edvin says, "If I add two even numbers, the answer will always be even." Is the student correct? Prove your answer with an equation. Then, explain what happens when you add two odd numbers. What if you are adding doubles?
Yes. For example, 4+6=10 (even), and 3+5=8 (even). Both sums can be even. Doubles facts will always make even numbers.