Problems of the Day
Mara has 4 toy airplanes. Luca has no toy airplanes. How many airplanes do they have altogether?
4 + 0 = 4
5 + 4 = 9 and 9 - 3 = 6. Are these related facts?
No. They do not use the same numbers to add and subtract.
Jake had a party. 4 girls and 5 boys from his class came. How many of Jake's classmates came to his party?
4 + 5 = 9
There are 10 apples on the tree. 6 fall off. How many apples are still on the tree?
10 - 6 = 4
There are 6 juice bottles on the shelf. Tim and Kim drink all 6 of the juice bottles. How many juice bottles are left?
6 - 6 = 0
There are 8 lizards. 6 of the lizards run away. How many of the lizards are left?
Use the numbers to write an addition number sentence.
8 - 6 = 2 lizards left
2 + 6 = 8
Which two numbers can Mike add together to make 19?
a) 7
b) 14
c) 5
14 + 5 = 19
There are 4 children in Lily's classroom. 4 of the children are girls. How many are boys?
4 - 4 = 0
A toy store has 40 robots. The store sells 30 of them. How many toy robots are left?
40 - 30 = 10
These number sentences use the same numbers. What do we call 4 + 1 = 5 and 5 - 1 = 4?
Related Facts
Wendy feeds her dog two kinds of treats. Yesterday, Wendy fed her dog 6 peanut butter treats and 6 carrot treats. How many dog treats did Wendy feed to her dog in all?
6 + 6 = 12
The shoe store has 9 shoes. 2 of the shoes are black. The rest of the shoes are red. How many of the shoes are red?
9 - 2 = 7
There are 12 children in the park. Some of the children go home for lunch. 4 children are still at the park. How many children went home?
12 - 4 = 8
Sam sees 15 birds sitting on a rock. 7 birds fly away. How many birds are left?
What is the related addition fact for the subtraction sentence?
15 - 7 = 8 birds are left
7 + 8 = 15
Which sum is more? 23 + 6 or 23 + 20
23 + 6 = 29
23 + 20 = 43
23 + 20 is more
Tom ate 10 oranges. James ate 2 oranges. How many more oranges did Tom eat than James?
10 - 2 = 8 more oranges
Lana buys 9 boxes of toys. There are 10 toys in each box. how many toys did Lana buy in all?
9 tens = 90
Andrew collects 10 shells. He loses 6 of them. How many shells does Andrew have left?
What is the related addition sentence?
10 - 6 = 4 shells left
6 + 4 = 10
There are 54 small dogs at a park. 4 large dogs are at the same park. How many dogs are at the park in all?
54 + 4 = 58
There are 26 children on the bus. 5 children get off the bus. How many children are still on the bus?
26 - 5 = 21