First Grade · Math · week 2

Count on: start big, hop the small

Use the count-on strategy -- start at the bigger number and hop forward the smaller number -- to add within 20.

When you add two numbers, start counting at the BIGGER number. Then hop forward one hop for each of the smaller number. It is faster than counting both numbers from zero.

For 3 + 9, do not start at 3. Start at 9 (the bigger number) and hop forward 3 times: 10, 11, 12. So 3 + 9 = 12.

📋 For the teacher
Teach it (10–15 min):
  • Say "start big" together before every problem this week -- it becomes a habit fast.
  • Hop along a number line or a hundred chart, one hop per count, so the strategy is visible.
  • Let your child close their eyes and picture the hops instead of using fingers, once they are ready.
  • Watch for a child who still starts at the first number written even when it is smaller; gently redirect to "which is bigger?"
Talk about it:
  • In 4 + 9, which number should you start on?
  • How many hops do you take for 9 + 2?
  • Why is counting on faster than counting both numbers from the start?

Mastery looks like: They automatically identify the bigger number and hop forward the smaller number to add within 20.

Common stumbles: Starting at the first number in the problem rather than the bigger one; losing count partway through the hops.

See it visually

Interactive, spoken-aloud tools that show this idea in motion.

AdditionSee groups combine — with counters, blocks, and the number line.try →Counting & Ten-FramesCount objects in ten-frames and base-ten blocks, one tap at a time.try →Number LineCount, add, subtract, and skip-count with animated hops and a friendly voice.try →
Homework for this lessonType it, write it with a stylus, or print it for pencil & paper.open →
Records attendance + 15 min of Math for this learner.
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