1
Review: add and take away
Joyful Mathematics: Chapters 5–7
GoalAdd and take away with numbers up to 10.
New words
add · join groups to find the totaltake away · find how many are leftsum · the answer when we add
Explanation
Let us remember. We add to join groups. 4 peacocks and 3 peacocks make 7 peacocks. We take away to find how many are left. If 2 of the 7 fly away, 5 are left. The sign + means join. The sign − means take away.
Worked examples
8 − 3 = 5. Three lemons are crossed out.
9 − 5 = 4. Start at 9 and hop back 5.
5 + 5 = 10. The frame is full.
Class activity
Two stories. Put 8 buttons on a cloth. Tell an add story: "4 buttons are in a box and 4 buttons are on the cloth. How many altogether?" Then tell a take-away story: "There are 8 buttons. 3 roll away. How many are left?" Swap with a friend.
Practice
1
How many altogether?
9.
2
How many are left?
4.
3
What is 7 + 2?
9.
4
What is 10 − 6?
4.
5
Riya has 6 hair clips. At Onam her aunt gives her 3 more. How many hair clips does she have now?
9. 6 + 3 = 9.