See how many red dots are on the ten-frame. First guess "How many more do I need to make 10?", then check your answer!
How do you add 7 + 5 in your head without counting on your fingers? The secret is number partners of 10 โ two numbers that add up to 10. 1's partner is 9, 2's partner is 8, and 5's partner is 5 (itself!).
Once you can recall these partners instantly, addition and subtraction get much easier later on. For example, 7 + 5 becomes quick if you add 3 to the 7 to make 10, then add the leftover 2 to get 12. Why 10? Because our number system is built on groups of ten โ 11 means "one ten and one," and 23 means "two tens and three." Look at how many dots are on the ten-frame and guess how many more you need to make 10.