Doubles or Not
What is a doubles fact?
An equation that has the same addends/parts/numebrs.
For facts to be in the same family they have to have the same ________ and _________ .
Parts and whole
Mr. Wright had 4 apples. He buys 2 more apples. How many apples does Mr. Wright have in all? Write an equation that will help you solve this problem.
4 + 2 = 6 / 2 + 4 = 6
Make a 10 to solve 16 - 8 = ?
16 - _____ = 10
10 - _____ = _____, so
16 - 8 = ______
16 - 6 = 10
10 - 2 = 8, so
16 - 8 = 8
What symbol do you use when you add?
A plus sign. +
Is 4 + 4 a doubles fact?
4 + 4 = ?
Yes.
8.
Which addition equation can help you solve 8 - 2 = ?
Choose all that apply.
*Hint: there are two
A) 2 + 8 = 10
B) 2 + 6 = 8
C) 6 + 2 = 8
D) 8 + 2 = 10
B and C
2 + _____ = 9
9 - 2 = _____
The missing part is 7.
Make a 10 to solve 6 + 6 = ?
6 + ____ = 10
10 + ____ = _____
6 + 6 = _____
6 + 4 = 10
10 + 2 = 12
6 + 6 = 12
What symbol do you use when you subtract?
How do you know the following equation is NOT a doubles fact?
6 + 9 = 15
The addends/parts are not the same.
Which related addition fact can help you solve 13 - 8 = ? Choose all that apply.
*Hint: there are 2
A) 8 + 7 = 15
B) 5 + 3 = 8
C) 8 + 5 = 13
D) 5 + 8 = 13
C and D
Use an open number line to solve 8 + 6 = ?
Number line should start at 8 and count forward 6 spaces until you get eo 13.
Make a 10 to solve 13 - 5 = ?
13 - ___ = 10
10 - ____ = ____
13 - 5 = _____
13 - 3 = 10
10 - 2 = 8, so 13 - 5 = 8
Addition equations go
______ + ______ = _______
part + part = whole
What doubles fact that can help you solve 4 + 5 = ____ ?
____ + _____ = ?
4 + 4 = 8
so
4 + 5 = 9
Which is NOT a related fact for 9 - 4 = 5 ?
A) 4 + 5 = 9
B) 5 + 4 = 9
C) 4 + 4 =8
C.
7 cars are in the garage. 8 more cars join them. How many cars are in the garage now? Write an equation to solve the problem?
7 + 8 = 15 / 8 + 7 = 15
Make a 10 to solve 8 + 9 = ?
8 + ____ = 10
10 + ____ = _____
8 + 9 = _____
8 + 2 = 10
10 + 7 = 17, so 8 + 9 = 17
Subtraction equations go
_______ - _______ = ________
whole - part = part
Finish the doubles fact.
10 + ____ = _____
10 + 10 = 20
Write one addition and one subtraction equation using the numbers 3, 8, 5.
3 + 5 = 8 / 5 + 3 = 8
and
8 - 5 = 3 / 8 - 3 = 5
Mike has 4 stickers. He buys 6 more stickers. He wants to keep 5 stickers for himself and give 3 to his mom. Will Mike have enough stickers to give to him mom?
Yes. Mike has 10 stickers. If he keeps 5 stickers he still has enough to give 3 to his mom because 10 - 5 = 5 and 5 is more than 3.
Make a 10 to solve 15 - 6 = ?
15 - ___ = 10
10 - _____ = ______
15 - 6 = _______
15 - 5 = 10
10 - 1 = 9, so 15 - 6 = 9
There are 17 balls at the park. 8 balls roll away. Blake says there are 7 balls left at the park. Do you agree or not agree with Blake's thinking?
Not agree because 17 - 8 = 9, so that means there are 9 balls left at the park not 7 like Blake thought.