Math Picture Book Post #5: 100 Snowmen

I’m not usually a fan of equations in math picture books. But I like 100 Snowmen by Jennifer Arena and Stephen Gilpin. On each page, students can use the mental math strategy of adding one to a double to determine basic addition facts to 19. Each number is represented as both a number to be doubled and one more than a number to be doubled. Take five. Here, students can double five and add one more to determine five plus six.

5 + 6 = (5 + 5) + 1 = 11

Here, five is not doubled, but one more than four, which is doubled.

5 + 4 = (4 + 4) + 1 = 9

Dot cards can be used to draw attention to the doubles plus one strategy. Ask “How many do you see? How do you see them?”

Doubles Plus One Cards

To practice this strategy, students can play a game.

Taking turns:

• Roll a ten-sided die
• Build the number
• Build one more than the number
• Cover the sum with a transparent counter

The first player to cover all of the sums wins.

Snowmen Doubles Plus One

On the last page, every single snowmen is added.

This suggests a different mental math strategy: making tens.

(1 + 2) + (3 + 4) + (5 + 6) + (7 + 8) + (9 + 10) + (9 + 8) + (7 + 6) + (5 + 4) + (3 + 2) + 1

(1 + 9) + (2 + 8) + (3 + 7) + (4 + 6) + (5 + 5) + (6 + 4) + (7 + 3) + (8 + 2) + (9 + 1) + 10

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